I visited Buffalo yesterday from the Toronto Area for the "Winterfest" (it was interesting but smaller than I though, the highly was the free tour offered by the Buffalo Hiking Group) but I discovered the LLoyd's Taco Truck when I was there:
I had the pork taco and I really enjoyed it. Just an hour earlier we stopped and The Swanee (sp?) Tavern and had some wings (was recommended on our tour by some guys who worked in the mills around that area)... interested atmosphere but I have had better wings elsewhere.
Anyway, back to the taco truck. I understand from the guy's working there/own that these type of vendors are fairly new in Buffalo. In Toronto they are pretty much non-existent outside of hot dog and french fry vendors and a failed attempt at "carte" service.
I highly recommend checking this guys stuff out. Oh and the aztec hot chocolate was very good too (2nd to the one they have at Distillery District in Toronto but still up there in my hot chocolate rankings :) ) and reasonably priced!