What is the best way to set up a single forum to serve multiple sites?

[JS_Harris]

I'm posting this in Google search because Google and search rankings are my concern.

I own 3 sites about a very similar, and seasonal, topic. Think summer widgets, winter widgets and foreign widgets.

I'd like to launch a single forum on one of the 3 sites, likely the non seasonal site, and link the other two sites to their section of the forum from the comments section of each page... "leave a comment or come discuss this with us in the forums" is what I'm wanting to offer.

My concern is the obvious, penalties from Google for cross-linking excessively. The links are only useful if found on every article, would I be better off with 3 seperate forums? Is there a way of letting Google know it's a shared forum?

Thoughts?

[tedster]

My concern is the obvious, penalties from Google for cross-linking excessively.

Use rel="nofollow" on the cross-linking and that concern goes away.

[bwnbwn]

I have done the very thing you are intending to do without any problems. You can add the no follow if you prefer as Tedester indicated but I didn't and no issues been this way for over 2 years.

Your not trying to inflate PR or trick rankings but provide a way of communicating. Takes high numbers of traffic to run a forum.

I link to the forum from each "sitewide" header 4 sites on the shared forum and have a header link in each site to the forum.

[HuskyPup]

I second bwnbwn, no problem, I link between many sites and they are not seen as deceitful but helpful by G.

[JS_Harris]

My feeling on nofollow is to place on any link I don't control and that leads to a site I can't safely vouch for. My own sites don't apply but that doesn't mean I'll avoid getting penalized.

bwnbwn do your users ever mention it feeling "odd" to be switching sites to use the forum?