During an entire weekend, artists from the Abbeyhill colonies (block of houses in the London Rd and Easter Rd area) open their homes/studios to present their work.
website and their facebook page.
I actually got to know the event thanks to one of the numerous meetup groups I joined since I moved to Edinburgh: The Edinburgh High Brow/Low Brow Culture Group. It's a really nice group with friendly people interested in art and everything cultural.
Feel free to leave a comment or send me a message.