PS2-Linux works with rdesktop to open a very usable remote desktop connection to a Windows XP computer. I've done it recently. It does NOT work great for viewing video files (too choppy), although playing music (less bandwidth) worked fine. For running regular programs including email, web browser (other than playing videos), music player, etc. it works just fine.
I had to download and compile the rdesktop package under PS2-Linux on my FAT PS2 with a HDD. Since PS2-Linux takes a greater amount of work to install and configure than homebrew, it may not be a good solution for many.
PS2 v9 NTSC, PS2 v12 NTSC, PS2 v15 VESA