A search on Twitter for Tumblr shows some very upset users (some comments NSFW) about the outage. We’ve sent inquiries to the Tumblr team for more information on whether this was a planned maintenance period or if the outage was caused by something else.

This is the first time that we’ve reported that Tumblr is out of service.

As always please report in if Tumblr is down where you are – either the main Tumblr site or your personal Tumblog.

Update: 6:45AM Eastern – Tumblr is back!

Related: Our Tumblr coverage including overview video from Tumblr founder David Karp.

Here are the NYC-based companies on the list (in alpha order):

• Drop.io (our coverage)
• GiveReal
• Hercules Networks
• Tumblr (our coverage)
• VIVO Natural Products

Most of the companies are headquartered on the East Coast! Go checkout all of the listed companies and then vote for a NYC-based company.

TumblUpon may sound very similar to another service, StumbleUpon and from what I can tell the basic functionality is the same. As you “like” posts on Tumblr, it learns about your likes and when you use the TumblUpon option, Tumblr will recommend other posts you may like.

TumblUpon uses a frame (grr!) to move from one Tumblr page to another. It allowed me to jump around even though I have never used the like function on Tumblr.

This is an important move by Tumblr as it will help keep readers inside of their network and will help with discovery, something I believe in strongly.

Mashable has additional thoughts on TumblUpon and some metrics that Tumblr will release today.

Content can be submitted by email or Web and the form for submissions is customized by each Tumblr blog owner.

This type of content submission has become popular. Many blogs are taking “contributed posts” more and more. Another example, comment service Disqus allows bloggers to take comments left on their site and turn them into full posts. We will see more of this type of submitted content in the future.

You can either upload photos or link out to other photo locations (flickr, photobucket, smugmug, some porn site, etc.). Additionally you may link your photo of your dog willy to his twitter page.

Unfortunately it does not appear that there is any option to embed a photoset outside of the originating Tumblr site. This could be a great way to get Tumblr content further along the Internet highway as long as the photoshow links back to the Tumblr site.

If you are new to Tumblr, check out CEO David Karp explaining how Tumblr works.

When Tumblr raised their first round of venture capital ($750k) last year, the company shared a figure of 75,000 users and that they reached traffic levels in 2 months that it took Digg 8 months to reach. Kafka also spoke with CEO David Karp who noted that they will be working towards launching a freemium model early next year. The freemium model means that you get some features for free and others you pay a small fee for.

This past June, CEO David Karp provided a business update about Tumblr which I caught on video (embedded below). At that point, David noted that Tumblr has 310,000 users (no word on active), 120,000 posts per day and they host 15,000 custom domains.

If you are new to Tumblr or want to learn about the company and their model, check out this video from June with Karp.

This service even includes new services Posterous and Identi.ca.

People referenced in the video: Sarah Perez, Marshall Kirkpatrick, Robert Scoble, Louis Gray, Steven Hodson, Corvida and Steve Rubel. Our special tickettaker is Tamar Weinberg.

For some stats, David noted that Tumblr has 310,000 users (no word on active), 120,000 posts per day and they host 15,000 custom domains. The user number is up from 75,000 last October.

The first video has the puppet (Gary) interviewing Tumblr founder David Karp about what makes Tumblr so popular. Rather than give away the reason, just watch the very short video.

In this video, the puppet asks MobLogic host Lindsay Campbell and Wallstrip host Julie Alexandria how to keep viewers engaged. This could be the first time that Julie and Lindsay have appeared together!

Update – Thursday – Jakob Lodwick notes that this .org site is not his either.

This past Saturday, Lodwick posted about some new domains that he registered. The list includes:

• D***S***.COM
• BA******RO****.COM
• n*****.com & .us
• n*****s.com & .us
• n*****ist.com & .org
• n*****ists.com& .org
• n*****ism.com & .org

The previous day Lodwick posted that he had dinner with Karp per his blog post and calls Karp a, "soon famous face."

This is where Thomas went to work. After some Columbo-type maneuvers, we know the full names of some of the domains that Lodwick registered:

• norbum.com
• norbum.us
• norbums.com
• norbumist.com
• norbumist.org
• norbumists.com
• norbumists.org
• norbumism.com
• norbumism.org

Anyone know what a Norbum is? Let’s complete the picture before the new year rings!

Photos by: David Karp & Zach Klein

Tumblr

• They are very big in Japan
• Tumblr reached the same traffic levels in 2 months that it took Digg 8 months to reach
• Scott noted 75,000 users – How many active?

Peter at SAI has some additional financial details on their $750k funding which he says makes Scott a paper-millionaire.

Here is one thing I haven’t seen mentioned: tumblr is a spammer’s dream. It gets Google indexed and more importantly, Technorati considers it a blog so it gets indexed in the inbound count. Just wait until the spammers realize this!

For examples, see http://netneutralitycanada.tumblr.com/ and http://project.ioni.st/

My initial question is sans mobile/sms, is tumblr a better twitter? tumblr allows you to capture your thoughts but offers you more without being as intense as a full blog. Instead of moving to a place where we post tiny 140 character snippits, tumblr allows you to grab and share things from your life and the Internet easily and quickly. Short-form is hot right now and tumblr appears to have it nailed spot on.

Found a great video? tumble it and others can see it. Same with chat logs, photos and links. Of course you can post larger blog-style entries as well.

I could easily see tumblr woop twitter in a 10-round KO if they were to add mobile, IM, and friends. Perhaps I would leave out the followers.