From memory (so, possibly a few missing):
Chun Quoit
Glimpse of Lanyon Quoit
Boscawen Un
Boleigh Fogou
Long Meg
Stenness complex
Callanish
East Aquhorthies (sp?)
Various Dunnydeerish Aberdeenshire circles
Avebury
As 4W says, about an hour long. :^)
love
Moth