On top of having an amazing founding story, Greplin is one of the most useful tools out there. Greplin indexes all of your web-based data (Facebook, Twitter, Linkedin, Google Apps, etc) and provides lightning fast search access to all of it. I can’t tell you how many times I’ve forgotten ‘something’ and been able to dig it up through Greplin. There are so many ‘something’s spread out across all of the data I’ve posted to services like Facebook and Gmail that a tool like Greplin becomes invaluable. Add this to the fact that Facebook and Twitter have very poor search implementations, and you have a must-have tool.
I know many probably shudder at the thought of a service that essentially indexes your entire life. To be fair, you already put all that data up in the cloud so you’re pretty much fucked anyway, especially with SOPA on the horizon. You might as well have a fast and efficient way of accessing it. For the techies out there, they probably have one of the more interesting Lucene implementations I’ve seen, with a lot of cool hacks built in.
Greplin now lets you index Google Apps accounts for free. This used to be a pain for me because my GMail account is technically apps through Stanford Alumni. Another plus for a great service.