How do I hook up my little mp3 player to my '05 scion xb

Dude l think you cant hook up mp3 players.only ipods.because l have a scion tc

if you have a auxillarry plug just buy a jack plug pin and plug it in there at radio shack for instance and make sure the audio is converted to the right format

Cassete adapter / FM transmitter.maybe if you have an auxillary jack you can go to circuit city and get a 3.5mm(most newer headphone is size) to 3.5 mm jack, or adapter for any size really.

But instead you should sell me your xB for around say.$20 and l will give you a way better home stereo with everything you want on it. AND AUXILLARY JACK!

Look in between the seats by the parking brake you should see a little door marked AUX, open the flap and plug in a patch cable. You can get one from radio shack but the one l purchased did not last very long.
Change the radio setting to AUX and away you go.
Thats assuming you do not have the ipod radio, on that l do not know. If all else fails read your owners manual.

get an fm transmitter

even if your Scion is equipped with the IPOD capable radio, you still have the AUX plug in. you just need a standard 4.5mm stereo cable to plug in. You should be able to find that at any radio shack, best buy, etc.