I've been using this on my work computer for the past few months, and it is sooooo quick. My usual rig for posting and just surfing the web (and maybe a bit of casual photoshop/itunes/etc) is a Macbook Pro 2.4ghz 15" with 2GB RAM, basic onboard video, and the works. It's pretty zippy already, but NOTHING compares to the i7 860.
It's probably the best bang for your buck you'll ever spend; it retails for something around $250 at the time of this posting. Anyways, look into it, especially if you're thinking about updating your rig.