I should also note that the net cost of the bike was about $75 - Schwinn from thrift shop, stem and seatpost from eBay (could have done OK with the original steel post but it was so tacky
), cog, lockring and chainring spacers from Harris, minus the derailleurs and freewheel I took off and sold on eBay. Cheap thrills indeed.
Another thought on hills: What you don't have on a fixed gear, even when standing and mashing, is that "dead spot" at the bottom of each stroke. The momentum smooths out your pedaling stroke and seems to make it less fatiguing. But then again, I have yet to try it on a "real" hill.
Tomorrow is supposed to be a decent day so I'll try it on a course with some long but not too steep grades and a couple of short steepish ones that are usually pretty tiring on my roadie.