Tonight, TUAW has a couple of last-second deals for you from the iPhone App Store:
Air Sharing Although Avatron's Air Sharing software will eventually sell for $7, they're offering it for free for the next couple of weeks. Air Sharing allows you to mount your iPhone or iPod as a wireless drive on any Mac, Windows or Linux computer according to the Application Description writeup on iTunes.
Text Guru For the next 24 hours, you can pick up a copy of Brancipater Software's Text Guru app for just $0.99. It normally sells for $5. it provides an iPhone-based multi-function text editor that includes cut/copy/paste (inside the app, not between apps), file sharing and email support.