Robin is right - the indavidual blocks are much better then trying to edit the templates in the database.

Can it be done?

Yes - but its just easier unless you want a banner.

One hint - if you are proficient at all in flash, you can create a banner ad to replace the standard logo.swf - that said, you can also encode that swf file with affiliate links or whatever else you may be wanting to link to externally.

S