How did you make the layout? Graphics design is my biggest weakness, all my webapps look like the design is made in Paint. And yours is so clean, the fonts are good, everything looks so professional.
I make extensive use of http://twitter.github.com/bootstrap/ (a godsend for hackers), though I use it more as a style-guide and rebuild most parts myself.
The ui/ux evolved in this app, which means I started with the bare minimum requirements (it looked bad. really bad) and continually improved the "look & feel" as needed. No photoshop involved.
It's still not finished, but it has come a long way :)
