You may want to check out iTap (a non jailbreak app, its in the app-store) for iphone also, I think I've come to the point of figuring out that it's been the best app that closely represents apple's touchpads on the macbook like of computers, it also has a keyboard with native volume control buttons and other little features.
itap also works in windows in case you want to give Centrafuse software a try, I've been using it for a year, I really can't find a reason to go back to roadrunner other than it IS free but not solid enough for me to stay happy with. If I were a software developer I'd just make my own, wish I was, but I'm not, heh.
Way to go though with the 3G tethering, using PdaNet? That's what I've been using and it seems to be pretty fool-proof, the newest version doesn't run my battery dead while it's plugged in.