how would i continue execution while updating a progress bar?

[<nuke bayside net>]

i think the subject says it all. i need a good way to make a progress bar
and update it while my program is running. once gtk_main() is
executed, my program stops and waits for events. to be specific, i'm going
to hack up GNU Make to show progress of each current job. except for this
little oversight, it won't be hard to do.

it'd be a great addition to Gnome for newbies compiling things if i could
get it to work :)

 _        _  __     __             _ _                                  _
|        / |/ /_ __/ /_____         |       Nuke Skyjumper               |
|       /    / // /  '_/ -_)        |         "Master of the Farce"      |
|_     /_/|_/\_,_/_/\_\\__/        _|_           nuke@bayside.net       _|