The latest build of the 2.0 firmware (now at 240d), now includes the option to save photos straight from Safari to your camera roll.
Simply tap and hold an image for a couple seconds, and a window will scroll up asking if you'd like to Save Photo or Go To URL. Save, and the photo shows up in your camera roll!
A perfect addition to our iPhone wallpapers section, browse to one you'd like, and save for use.
The 2.0 firmware will be released in June, but versions of it are floating around the net (don't link to them here, thanks) and can be applied and unlocked/jailbroken to your iPhone using the Pwnage Tool.
What other little new secrets are in the latest firmware? Find one? Let us know by shooting me a pm with a screenshot...