heheheh
Yes, the ability to sort by most fields are a great idea. One way to do that (and is something I've seen on my bank acct) is to make the titles for each column as links to their own sort function. Say you click on the title for the number of posts column and it sorts the listings by number of posts - most to least, click on the title for the location column and is sorts the listings alphabetically, click on the AIM field and it sorts putting those with AIM intros at the top, etc...
You could then remove the drop-down sort box from the top to clean up the interface some