Research some bands who you think would sound good performing your songs, buy their cds' and check the song credits to see if they perform other peoples songs. Mail a demo of the songs to their management company, or better yet, if they come to your town in concert try to get a demo to them personally.
You have to realize, most rock/pop acts don't want to record other peoples material because it means less money for them in royalities.
I tried it once, I wrote a song that would have been killer for Indigenous to record (a nice blues/rock peice w/some rippin guitar). I submitted it to them but unfortunately heard nothin in return. Maybe you'll have better luck then me.:)