Can a phone pretend to be a Bluetooth keyboard?

Question

It seems like it would be super useful if an app existed for iPhone/Android that emulated a Bluetooth keyboard or mouse. e.g., you turn on the app, and suddenly you can type on

Answer 1

I'm surprised nobody has answered pointing out BlueputDroid as an Android solution for that. At the link you can find further information about device compatibilities.

I know this thread is rather old but I think it's worth to let it documented so others would end up here as me and will find an answer, at least for the Android half of the question.

EDIT: if you have problems to get your device connected to your ps3 like I did, try this out: http://forum.xda-developers.com/showthread.php?p=19881739#post19881739