I recently came accross a company that markets toolbars by offering valuable software for free to end users (see Family Watch Bar Toolbar) and they sell network specific search positiongs that guarantee  visual placement on all of the major search engines.  I've purchased a couple of keyword placements from their marketing arm.  So far, the test has panned out well and if it continues, I might recommend these guys in lieu of rising PPC costs.  So far, I've acually generated a better cost per visitor with this "network leveraging" service than my campaign on Google (3 years of dialed in PPC and SEO campaigns for my company and 27 clients).  Of course, I'm not dropping my PPC campaigns yet.