I am aware that I can share my wired internet connection to other devices wirelessly, but what I need now is a little more complex. I am limited to one device over the wifi but would like my macbook to have internet as well. It's in another room so ethernet is not really an option. I really would like to share the wireless from my ubuntu (it's on more) to other wireless devices.

After some light googling I can't find anything even remotely useful as they all involve an ethernet cable at some point. Has anyone here had any luck with anything similar?

I am running 12.04 LTS just for reference and have a Belkin G wireless USB device. If anyone knows a possible procedure I can find out about the chipset etc. if needed. I understand there may be hardware limitations.