Is a mouse wheel worth it? I go nuts anytime I switch to a non-wheelmouse. I went through a big paperwork shuffle at work just to swap a perfectly good mouse for a wheelmouse.
Get a "microsoft optical wheelmouse". Don't bother spending the extra $$$ for their intellimouse explorer, just get the basic "optical wheelmouse". It costs under $50 and you'll never go back to non-wheel ball mice again. Logitec also has optical wheelmice but I like the microsoft shape better.