Brad Fitzpatrick is one of the most interesting programmers to watch. He's written a dozen really interesting and useful pieces of code. Whatever he's working on is probably worth your attention. Right now he's working on Go at Google.
Yes, another of his inventions (or something he was at least involved in implementing) is Gearman (http://gearman.org/), a queue/worker system which I used in my last job at a domain registrar/web host to hack up parallelised domain name look-ups. Similar to memcached, it was ridiculously quick and easy to set up and use, and bought me massive efficiency gains with very little implementation cost.
Whoa, he did gearman? That's awesome. I had no idea.
He also invented and prototyped OpenID.
Another good link is Brad's (old) company Danga Interactive - http://danga.com
He really is! He will also be on stage in Paris in 2 weeks at my http://dotscale.eu conference ;-) Come and meet him!