As for biking, if you're really interested in being able to bike, consider a pair of real biking shoes and clipless pedals, the kind that serious road and mountain bikers use (pedals are typically Shimano brand SPD for mountain biking, Look or Time brand for road biking). Real biking shoes have an extremely rigid footbed so that you literally can't toe off or flex the foot. This is so you can apply maximum leg power to the pedals, with the side benefit of being a good idea for PF sufferers. I wouldn't be able to bike without them. I originally had clipless on my road bike, but also had to switch to clipless on my mountain bike when I got PF. Standard shoes allow for way too much flex and strain on the plantar fascia. The down side is that pedals range from $50-$200 and shoes range from $60-$250. Be wary of the cheap biking shoes, the cheaper ones tend not to have the rigidity in the footbed that the more expensive ones do. Also, some of the mountain biking shoes are too flexible for my liking. www.nashbar.com and www.performancebike.com are two catalog houses that have web sites. My recommendation, however, would be to find a serious bike shop in your area, because usually those people will let you test ride to make sure that you won't have any problems with the pedals. A long test ride should let you know if they're ok for you. They might even have used pedals that they took on trade, etc.
Good Luck.
PS: Swimming is a great exercise, as long as you wear your shoes right up to the point where you get in the water. No walking in bare feet!