Is a 3g 16gb Iphone able to download the latest apps?

I've just bought a 3g 16gb iPhone and am wondering if there are any restrictions because I have also got a 1st gen iPod touch and I wasn't able to download any apps on it. Is it a similar situation with the iPhone 3g or not

It's the same now, sorry

Unless you can get iOS 6 then it can't download them

It depends on what version of iOS is the minimum for the app. If it is higher than 4.2.1 then it wouldn't be able to be installed.