Just another follow-up...
I looked at the alternative 317 series pass regulator. Assuming max dissipation of 2 watts (max transformer voltage and 100mA LED load), a low-profile heat sink with about 15C per watt temperature rise is about the same size as the regulator board. And a heat sink and LM317T from Mouser actually cost more than the switching regulator at this point in time.
Without a heat sink, the LM317T temperature rise is 50C per watt. So the junction would be 125C at two watts dissipation without a heat sink - the max rating on the device. A 15C per watt heat sink would bring the case down to a more conservative 55C (about 130F), and the junction to 65C at 2 watts.
Of course a smaller heat sink could be used with more temperature rise, or the board copper used as a heat spreader for a surface mount LM317. But at this point I believe the switching regulator is the right choice. There is even a smaller one available on eBay for the same price, but it uses a regulator that is not recommended for new designs.
