How to delete songs on you iPhone

I downloaded a Rhianna CD onto my iPhone 3G. Then I downloaded Now 82 which has one of the songs from the Rhianna CDs on it, so now I have two of the same song:/ How can I delete songs then?

Through itunes on the computer

edit: i have the iphone 4 and i can swipe the song and "delete" comes up. Not sure if it works on the 3G

All you have to go on to your ipod, go on to, songs so there's the list of your songs, then for the song you want to delete swipe the left side of the box where the song name is and it should come up with delete, then press it and it deletes the song? X

Well, you can use your iTunes and manually delete it. But if you don't have it on your iTunes just yet, just go to the list songs and swipe it and it should probably delete. If its on your iTunes, i suggest deleting it from your computer on iTunes because if its on iTunes but you just swipe it, it will download back onto your iPhone when you plug it again and sync.

Simple and easy
1 plug iPhone to pc wait for I tunes to pop up. Once it pops up go to the lef said n it should say music press on it n you will see all your music than when you want to delete the just go to the song right click onthe mouse n press delete