glengara - 11:11 am on Dec 14, 2007 (gmt 0)

Must say I prefer the term "trusted" to "authoritative" as the latter implies a certain size/popularity which for most SEOs simply translates to high PR.

I look for link "justification" along the lines Zydo mentioned and check the SERPs for their navigational keywords, if their internal links pass value there's a good chance their OBLs will too....