AmpliTube iRig is pretty cool: plug your electric guitar into your iPhone and get a full effects rig for practice on headphones.

The system actually consists of two parts: a jack adapter with a headphone plug, and an app. You have a choice of three different apps, ranging from the free version to the more expensive AmpliTube. The effects doesn’t sound like they’re the best ever, but as a practice device this must be very handy.

The app should work without the iRig plug too, if you can find a suitable Y-cable from somewhere else.