Sorry if this question has aleady been asked ... I've been looking around for hours with no solution.

If I have multiple computers, may I use the same wallet on multiple machines to increase the rate of which I generate bitcoins? If not, what would happen if multiple machines had the same private key?

As another offtopic question, on Arch Linux is there a GUI available? I'm using the daemon right now and it seems like it would be fairly simple to build one upon it so if there isn't one I could write a GTK+ one or a QT4 one.

Thank you!