Social bookmarking and SEO

[JohnGBSA]

I have set my forum up to have small social bookmarking icons at the bottom of each post in a thread, so my question goes to that.

While I realise that social bookmarking is very useful, I am not entirely sure how it effects SEO as spiders may class them as outgoing links especially if they appear very often.

I would appreciate feedback as to what the SEO consequences of it may be.