QuickSnap - Very simple application that makes up (slightly) for not having a dedicated camera button.
Install the application, put a shortcut to it on your homepage. Shortcut will open (as quickly as possible) a preview window. Tapping anywhere on the screen will take a photo. Back button to exit.
QuickSnapNoAutofocus.apk - Takes pictures instantly, but you need a steady hand or your picture will be blurred!
QuickSnapAutoFocus.apk - Takes pictures using autofocus, so there is a delay while it focuses, but the pictures can't be blurred.
Saves the images to internal sd card as $DT.jpg on a separate thread. Multiple taps on the screen to take lots of pictures quickly. (Supports multitouch!)