Alright a close friend surprised me, my brother and our other friend with the news that he's moving to Florida for work because of the current job market, and he's going to buy a X-Box so we can still play together.

The thing is my brother got a 360 (about two years ago, anyway) and we both have separate gold accounts. So I was wondering if we can play Rock Band 2 or the Halo 3 campaign splitscreen (or any other game) with two other friends online while the two of us are on the same console?

Yes, your local friend should be able to log in as "Guest" on your console and join your band or Halo team.

I think you answered my question, so thanks, but just in case I worded it wrong.

Me and my brother share a 360 and we both have gold accounts, one friend also has a 360 and gold, and the friend who's moving says he'll get a 360 so we can all play together, so there won't be a problem with me and my brother on the same console?

With Halo and Rock Band no, there are some games that don't allow splitscreen so you're screwed with those but with the 2 you mention you should have no troubles.

Cool, thanks.

Me think Rock Band has no splitscreen, but it shows the progress of all four band members.

For Halo, no, but the two of you would get seperate screens for both your characters.