Try Gnip – My friends at Gnip have just launched a free trial service. Making it all self-serve radically lowers the barriers to just giving it a try, so if you're at all interested in sucking down masses of data from Twitter, Flickr, etc, you really should give it a shot.
The Hotlist – There's tonnes of information about what our friends are up to flowing around us these days, but it's far too time-consuming to actually make sense of it all. That's why I love this mashup of your social graph, Facebook events and a map to help you discover events you should care about.
Jumppost – It's really hard to uncover the information you need to find good apartment rentals, especially if you're looking more than a few weeks ahead of your moving date. These folks have figured out that existing tenants know when their lease is up, and are willing to pay them up to $500 to pass that information along to apartment hunters.
Everlater books – My old Techstars colleagues Nate, Natty and Ryan have been doing an awesome job with their service that makes it much simpler to share your travel memories than the alternatives of email, blogs or Flickr albums. Now they've made it easy to create books from your trip diaries, and the quality of the examples I got to handle was impressive. If you order one today, you'll get free shipping too.
Super-simple Storage Service – I've been frustrated by how much complexity is introduced into my processing pipelines by actually having to read data, so S4's new write-only storage engine promises to radically simplify my code. At $12 a year for a terabyte of data the price is right, and AT&T's adoption of it for their customer complaint database proves it's ready for enterprise use.