A couple of biker friends have Ram Mounts for their iPhones - we use them as active GPS units - and they seem to work well. Nice mounts, easy to install and use, all that stuff.
I don't wear my glasses when riding (they're for reading, anyway) so I can't see the screen. Instead, I have the phone set up for total hands free, just use earphones and put the phone in one of the fanny pockets of my tunic. Over 3,000 miles that way (including falling off the bike path towards the Potomac River) and never had a problem or had the phone fall out. It's a hoot when I get a call from someone on the SOC while I'm out riding - people don't expect you to be talking while riding along on a bike.....