HomeDepot and now Lowes carry a small screwdriver with interchangable bits.
They seem to be of good quality, but you will use the T-6 more than the others and it will wearout faster. These screwdrivers are priced ~6.00 and I have used (2) for about (1) year. When the bit wears, you can grind a little (the worn part) off and bring it back to life.
Hope this helps. *want to add, I use mine quite often and for the average user they should last a long time.