Foldershare, set to sync my utils folder, which includes putty, teracopy, some gnu command line utils, a couple of scripts to start and stop services, .net reflector, keepass binary, notepad2, and some other portable apps that I end up collecting over time.
Dropbox, mostly for the public folder. The explorer/finder integration is a wonderful piece of magic. Dropping a file on the public folder and using the "Copy the public link" item on the context menu ended up being my favorite way to share files with the world.
