tswum:

Thanks for bringing this up. I learned from looking around on the net that it is "used" plus an infinitive. I'd not thought about it before and I would have said that it was one of them pesky compound word verbs: used to. Sort of like look up, which was the subject of some discussion here a while back.

I had never seen one like it before, so when I was at the fashion library I looked up her skirt.

TEd