As far as I'm aware, all free Tripod sites use popups/unders and you have to upgrade (i.e. pay) to have these 'Ads' removed (it's $4.95 USD minimum). Can't speak about Angelfire.
(p.s. James - I had trouble posting last night - you can see my message is there twice as well. Pressing 'Submit' seemed to do nothing - so I cancelled and pressed again.)