You've seen the ads before... speed up your browsing by paying an extra $5/month to your ISP for web acceleration. It pre-fetches and compresses sites for you, as well as sending only incremental change data where possible.
Well, you can get it such a product (but in beta) for free now at
http://webaccelerator.google.com/, except this one is unique in that it's not targeted at low bandwidth dialup internet connections. In fact they say you might not see much difference with a dialup connection. They specifically say it's "[size=-1]Designed for Broadband[/size][size=-1] – Web pages load even more quickly on DSL and cable connections[/size]."
No benefits for downloads like MP3s, or https:// pages for security reasons. But I think it's really interesting if it ever becomes available for mobile browsing and for low bandwidth connections. But everything is going broadband, so it might be a losing proposition to spend too much development money on that direction.
I really like Google, but don't know that I'm that comfortable with them handling all my data on their servers. On the other hand, they already know everything about my surfing because I search through Google.