We are big fans of CamRanger, while other options have been around for a while (both DIY and pro) they came up with a well packed product for camera remote control that has all the features you can possibly think about.
But if you are looking to spend a bit less money, don’t care about appearances and have the extra time to fiddle around, here is an Android driven alternative for $30. This hack from DSLR Film Noob is using an android tablet and a TP-LINK TL-MR3040 wireless router. It does require a bit of firmware hacking, but nothing that exceeds jailbreaking a phone or updating an Xbox.
Filmnoob reports that this configuration works up to about 30 feet when having line of site