It’s pretty simple, actually. You need fontforge, which should be just an urpmi/yum/apt away.
Then you do run:
$ fontforge -script - > Open("your-font.pfb"); > Generate("your-font.ttf"); > Quit(0); |
Finish input with Ctrl-D … that’s it!
Shamlessly stolen from http://typophile.com/node/14342 with thanks.