I also have two friends who got infections from pedicures -- one of them had to have a toenail surgically removed and the other had her pinky toe amputated.
Since then, I have decided to do my own at-home pedis because I don't want to lose a digit. The Barielle 60 Second Mani-Pedi is a dream come true for DIY-ers -- it's a scrub that whisks away scraggly cuticles and dry patches, and it moisturizes so you don't even need lotion afterward.
Barielle's celebrity nail technician, Elle, is also skeeved out by public pedis and gives this advice for saving your feet from nastiness.
Bring Your Own Tools: Sharing tools like files and scrub brushes spreads germs, so the technician should use a set on you and you alone. If they don't provide fresh tools, bring your own.
Beware the Foot Tub: Elle says the spa foot baths are a breeding ground for bacteria (eew!), which commonly settles in the jet streams. Even if a spa sterilizes the tub, make sure they run the jets for 10 minutes with a hospital-grade solution to flush out germs.
Ask Questions: Be nosy! Your technician should be able to clearly explain the spa's hygiene practices. If she can't, then vamoose!
Personally, I plan to stick with the DIY-ing for now. It saves money and I get to keep all my toes!