Its not the camera - later on i'll post some gig shots I did a few years ago with my 20D. (yes a camera able to handle noise better would do better - but the 20D is adequate with the right glass in the right hands)
your biggest restriction (apart from lack of experience which will only improve with time) is the lens (as discussed) I apreciate that you arent loaded but if you are going to do this a lot you need something like a 28-135 or a 24-105 (at big gigs you'd be further from the action so you'd need more like 300mm) - check out places like
mpb or even ebay for
second hand deals.
that aside gigs in pubs are a bitch to shoot because there isnt room to move arround and generally if you are at the front you are too close and further away you have people between you and the action - at the actual gig this wont be such a problem (though there'd be different problems like being tofar away)