Considering Sony Alpha A100 DSLR -- how important is image stabilization?

I am amateur photographer looking to buy my first digital SLR. Sony Alpha A100 DSLR has built-in image stabilization, but the reports are saying it has noise at high ISO settings. How important is IS for an amateur photographer versus better ISO quality in the Nikons and Canons? I travel alot in developing countries where it is usually not convenient to have a tripod, so IS would seem to be a big plus. Still, I'd like to hear from folks with more photography experience on whether this is a gimmick or whether this makes it a better deal than the Rebel XT or the D50/D80.