My situation is this: I use my n810 partially as an mp3 player, but even though my player has a hardware button enabled to skip tracks, it's hard to get to and I have to lock the device when I put it in my bag otherwise it will go all crazy.

Is there any kind of (preferably) bluetooth device which would simply let me press forward, back, pause, etc? Something that's recognized as a keyboard or something like that, and something that is configurable and doesn't require a USB dongle?

I find lots of articles about using the n810 to control things, but not little tiny devices to control the n810

hmm, there is keyboard support, so you can use a phone like a sony ericson i think. Also, I have heard that some bluetooth headset's buttons work, but I am not sure.

A Wiimote. Although it would be rather big for a simple remote.

I think if you have a a2dp headset with remote ( so you'll have the buttons to control the playlists), and if you install an a2dp patch on the n8x0 this will work. Unfortunatelly, if I'm not wrong the a2dp support for the IT's is limited to mplayer. Also I've read that the Canola team works on a2dp solutions, but for now I haven't seen a result. (Actually if you set Canola to use mplayer as a media engine it works, but the control if the mplayer is crappy)

Anyremote?

the problem with the SonyEricsson solution is that the NIT won't take command from the phone (or any HID compliant device) if it is locked ...
And I suppose it would be true for any other keyboard replacement solutions ...
May be you can try the buttons on a wired (nokia) headset ?

Ive seen some dedicated remotes, jabra had a cool on that was a wired headset coming off a remote you wore around your neck that looked like a dogtag. had skip, play, stop etc. Thing is though for remotes like that, they require the device to have the AVRCP bluetooth profile, which unfortunatly the tablets dont support.

Wiimote idea is actually feasible, but the battery drain / size may be a problem.