As an aspiring guitarist and total technofreek I bought some software so that I could combine my two loves. The software was Adobe Audition 2.0. This package allows you to mix several tracks at different times and then play them back. For instance I also sing, however my skill isn’t good enough to sing and play the guitar at the same time, so I record the guitar on one track and the vocals on another track.
The end result, I can sing and play the guitar! Not only this I can also download drum tracks from the internet, mix these in too and we have a band folks! An incredible piece of software that takes a little time to get used to but the rewards are astounding.