Ok, just want to clarify here. there are basically 2 ways to use Pogoplug
1) Software only. This is free. Leave your PC on, and you can copy folders from your PC to phone and vice versa. Pay a small fee and you can also stream directly from your PC.
2)Buy a Pogoplug device. I have one, it connects via Ethernet to my router. I have a 1 TB hard drive attached. I can access that drive from my phone to download or upload, and stream music and video. I also set up "Active Copy" on my PC to automatically backup my PC to the 1 TB drive. Very handy.
In any case, I highly recommend. I use it for my phone and my Tab and it's way cheaper than buying cloud storage, and remove the issue of who is storing your info. The only downside is if you're traveling and have a poser outage or something at home, you're screwed, so I keep my music on Amazon as well, so I always have access- but that's free (I only use 20 GB), so I'm not paying for it.
Oh- and since the USB hosting works in Honeycomb, I know some people with Xooms who have mnicroUSB to USB adapters that were able to attach thumb drives or (powered) hard drives, so you might wanna check over there.