Oh! My! God!
Mozilla mail imports .pst files!
Awesome.!! Half the reason I'm still using Outlook is that I could never figure out how to get my mail out of .PST files into something reasonable like an mbox. One reason to get off PST is this: whenever I archive a PST file to CD, Outlook won't read it back in - it tells me I don't have the permissions. Note that it will read PSTs from ZIP drives or if I gzip the PST first and then archive it and unzip later.
I'm so thankful for this. Moz is now my default browser.