How to detect wheter running on 3G or Wi-Fi on iPhone?

Question

Some lines of code? Any experience?

Answer 1

Since than I made a pretty simple block based Reachability wrapper that strips all the outdated C-like Reachability code, poured into a much more Cocoa form.

Usage like:

[EPPZReachability reachHost:hostNameOrIPaddress
               completition:^(EPPZReachability *reachability)
{
    if (reachability.reachableViaCellular) [self doSomeLightweightStuff];
}];

See Reachability with blocks for everyday use at eppz!blog, or grab it directly from eppz!reachability at GitHub.

It also works with IP addresses, which turned out to be a pretty rare Reachability wrapper feature.