I've just got the HTC Desire. Where are they about the same price? My HTC desire was free and then a £30 a month contract, the iphone would have been £169 or £149 depending if I went for the i4 or the 3gs.
Anyway I really, really like the Desire. I've never had an iphone but did play about with both in the shop. The HTC supports multitasking better and also supports flash. Its quick, battery life is good and there are loads of good apps. I was most worried about the apps but have found a good website called appbrain where I hunt for apps and then when I know what I want I download them via the market on the handset. There's a good range of apps and this is expanding all the time, all the ones I've wanted so far have been free. Oh and you can get Swype which you can't on an iphone. Believe me you need Swype!
There's been a couple of things that I've struggled with and apparantly the HTC isn't as user friendly as the iphone. It took me about 2 hours to work out how to sync my phone with the computer. But I'm not very techno minded, I've found a few forums where people are very helpful and tell me what I need to do.
You can expand the memory very easily on the HTC, Have just ordered a 16gb micro sd card for £25. The battery is removable unlike the iphone. So if you thought you were going to be away from a powwer supply for ages you could take another battery. Also if a better battery is developed then you could buy this and put it in.
Froyo which is a software update is coming any day now to the HTC Desire, its already been rolled out to the Nexus. Android are saying it will make the Desire 450% faster than what it is now.