If you want massive biceps, you need to work the large muscle groups of your body. You body wants to balance things out. For example, if you do nothing but bicep curls and don't do anything at all for you tri's, shoulders, or back, your biceps will not continue to grow huge. You wouldn't have the supporting muscles to counteract the biceps, so your body won't continue to build them.
I rarely do bi or tri exercises. I do a lot of multi-joint movements including squats, deadlifts, pull-ups, bench press type stuff (bar bench, db bench, pushups, etc.), shoulder presses, etc. I get a good workout to my bi and tri's doing this. Sometimes I will knock out a couple sets of curls or tricep dips at the very end of a workout just to get an extra burn.