1. Evernote, the best notetaking software I know of - it starts to serve me as an universal "external memory". The most undervalued software in 2009.

2. Live Mesh - something similar to dropbox, for syncing files between computers, while also provides online backup for up to 5GB of data

3. Executor - application launcher for Windows, combines best stuff from Launchy and AutoHotKey. You can quickly start app by starting to write it's name or by assigned hotkey.