Some minor suggestions/bugs:

1. It would be nice to have a button which pops-up a small calendar (something like on kayak.com or any other flight site). The automatic parsing is nice, but for the less web-savvy, a button would be easier to grok.

2. The time parsing is a little funky. If I type in 9:30, it auto-detects as PM. If I add a space after that, it suddenly switches to AM. This might catch people off guard.

3. The auto date parsing is awesome (with the 'natural language' feature). However, I found that the word 'tonight' doesn't work...perhaps you want to add it to your dict?