Any suggestions for sources for a good fisheye lense attachment?

Century Precision Optics, not cheap, but good.
http://www.centuryoptics.com/products/video/prodv/prodvfisheye.html

Hello,

Expensive also but of superb quality from OpTex (UK) is closed to fisheye (www.xl1s.com):

from the site:
Wide Angle Attachment Set
Comprises of two 0.7x optical attachments and a 89.1mm clamp ring. When a single 0.7x element is used a 30% increase in angle of view is observed. Two 0.7x elements (0.7 x 0.7=0.49) will give you a 50% increase in angle of view. Used in conjunction with Canon's 3x wide angle zoom lens a angle of view of 109.5 degrees is acheivable - equivalent of a 12.5mm SLR lens!!!

Will look at those manufacturers.
Thx very much for the replies.