I've thought about the logo thing - and come to the thought that, for me, it doesn't need to be anything more than the LR4x4 text as it appears in our browser.
I think we all refer to the site simply as : LR4x4. - and, for me again, the whole thing about the site is that it straight forward and doesn't need or have fancy branding.
So I'm not saying don't bother - but a mug with LR4x4 on with the forum blue represented somehow would be fine for me.