I have been doing drawings like this in my journals for years, but just recently discovered Zentangles on line! I have not stopped drawing samplers for two days! I will post mine when my camera is fixed. In the meantime, check out these links!
Design Originals' Suzanne McNeill's Zentangle Mask! Beez in the Belfry, Sandy Bartholemew's extremely helpful site. Home of Zentangle
Squidoo Lens on How to Zentangle
and browse around on Milliande's ning for all sorts of zentangle and general artsy goodness!