I wanted to share my mod to my SG3 after I upgraded from my N900. I tried to get used to the on screen keyboard but instead, I slapped on a bluetooth thumbpad to the back of the SG3. Here's my youtube video of it in action. Now that it even has a mouse on it, it's really a replacement for my N900. Although the level of support I got from lurking on the forums here is truly peerless. RIP N900, long live SG3!

Yep, nice that you are actually doing something but I don't think this is the final version of your idea? It kinda...doesn't fit? ;p

How thick? hehe

Yeah it has to be that way on purpose unfortunately. When I first did measurements, the thumbpad was just shy of the width of the SG3. But with the slider mechanism and the attach point for the thumbpad, I didn't have enough clearance in order to use the mouse portion without some overlap. Thus, it had to be skewed to the side.

As for the thickness, it ends up being about 3cm thick and with the added width, it's about 8.5cm wide now.

Yeah, it's definitely a Frankenstein only it's owner can love.

Looks nice for a first build. Wanted to do the same the moment I got an S3. Too bad I am way too poor. I'm also pretty sure there are smaller bluetooth keyboards on the market that would fit the S3 better.
Other then that great job

Ps: Rip n900? Hell no.