Same reason i had to get an iPod. I need a development platform to test my websites on. I was originally going for Notion Ink Adam, but after months of delays i heard about Archos and shifted my attention to that. The fact that it ran everything on my home server (comic books, mkvs, etc.) was icing.
When a decently priced Honeycomb comes out, i'll likely get one too.
Currently, my sisters laptop got busted and she's looking for a replacement. I'm having a bit of trouble convincing her not to get a Galaxy Tab. Her counter was that she has another laptop (her company laptop) for handling the heavy stuff and wants something she can carry around her condo.
I still think she's making a mistake and should prioritize getting a personal computer first. Galaxy tab is sold here for $800.00. You can buy a decent laptop for that!
OT:
I'm starting to think getting your site to run on all devices is pointless. iPod 3rd gen, iPhone 3gs, ipod 4th gen, iPad, Archos 101 (Froyo), Firefox, IE8, IE9, Safari. When you make an HTML5 site to run on one of them, it's guaranteed to be broken in atleast half the browsers i mentioned.
Rather surprising, considering the iDevices are supposed to be running the same OS with the same browser from the same company. One of my sites was made and tested to run on an iPad, with a codepath for iPod 3rd gen, last Christmas i got a 4th gen, ran my site on that, and it was broken. I've already been adding separate codepaths for iPod 3rd gen, iPhone, and iPad. Seems i have to add yet another codepath for 4th gen.
On the other hand, the flash sites i've made two years ago worked on my android tablet with no modification.
What did Jobs say about fragmentation?