Forum Moderators: skibum
I certainly don't think it would be considered unethical. An iframe is a reasonable solution to placing any "block of content" on your site. (Just make sure that the links inside the iframe will open a new window or tab, instead of loading the destination site into the tiny iframe window.) You aren't really "hiding" the content in the iframe, since Google can choose whether to include or exclude it from indexing (and computation of PageRank).