The DigiSpark wins hands down as the cutest little Arduino ever, and almost cheap enough to be disposable, which really reduces the potential fear of "screwing one up" in an electronics project (on the software side, of course, you just reset them, so that's no big deal.) It's really nice to see such a range of scales for adding "a little bit" of computing to something, while still having enough power to use some modern abstractions (USB, interpreted code) instead of banging out the bits by hand (uphill, both ways, in the snow... ehem.) Backed, made target, ends 10 September.
Scanbox really qualifies more for that other tech blog that I keep failing to start in that you could slip it in a backpack or briefcase and have a nice scanning "platform" for your phone - not necessarily enabling new things you couldn't already do with your phonecam, but taking them to a surprisingly "real" level of quality, helping "doing day to day business with only my cellphone" move further out of Dancing Bear territory. (Backed, already funded, should be available commercially at some point.)
The IO Rodeo Educational Colorimeter Kit actually arrived and looks quite nice; I haven't had time to assemble it, and in any case I expect I'll end up playing with it some and then passing it on to a high school science teacher friend, if I don't find some way to use it directly for tea and or chocolate experiments myself before the end of the year.
(I'm tempted to make a spreadsheet out of the Kickstarter Transactions page, just to add a "reward arrived" column; other recent arrivals include OpenBeam, the iZen Bamboo Keyboard, the eStylo and touchfire, and I have printrbot tracking info :-)