I recently bought an iPhone 4 and my sisters, who are 14-years-old, are super fascinated by it. My mom, now intrigued as well, wants to get them an iPhone for high school. Problem is, it has to be off-contract since the phones will be put on a prepaid plan. I managed to get an iPhone 4 16GB for $250 on eBay refurbished but assuming I can't get a deal like that again, it's going to be $500+ to get my sisters an iPhone 4. I know once the iPhone 5 (or whatever the heck it's going to be called) comes out, the 3GS would be exceedingly cheaper. Given my sister's needs, they'll only use it as a phone, texting, light internet browsing, and probably a few simple games (like Angry Birds or something); they're really easy to please and they're not a bunch of snotty teens. My question now: would they notice a really big difference between the two models? Is it better to just wait it out and get the 4 or will the 3GS suit their needs just fine (considering it's their first smartphone anyway)? I've looked through the forum and everybody says it's a bad buy if you get it on contract; since this won't be on contract, wondering it it'll make a difference or not. Any insight would be helpful.