The Samsung Galaxy Tab is the only Android-based tablet worth considering. But is it? That question is now up in the air since Barnes and Noble's $250 NOOKcolor, an Android-based e-reader, has been rooted. While before the deed was done it was just that - an e-reader - it's now taken on a life of its own, a life complete with Angry Birds:

The procedure is still a bit complicated (as you'll see for yourself below), but it's definitely a start - until z4Root, SuperOneClick, or some other one-click solution becomes available, I've got a feeling this is your best bet. It will only get better from here, especially once the device starts seeing its first ROMs.

Instructions follow:

[04:00:25] <[mbm]> http://www.multiupload.com/R6U2NEMXHI <- uImage
[04:02:27] <[mbm]> http://www.multiupload.com/MJY8SS8BAB .. there's the sdcard image
[04:03:10] <[mbm]> dd to an sdcard, wait for fastboot and then run 'fastboot boot uImage' with the previous file
[04:04:03] <[mbm]> when the kernel boots there will be a serial and ethernet device on usb
[04:04:29] <[mbm]> ethernet runs telnet and ssh
[04:04:37] <[mbm]> serial is a getty
[04:13:54] <[mbm]> usb ethernet on the nook is 192.168.2.2
So what you get is a new usb interface called usb0 (on both the nook and your linux box)
set the linux box's usb0 to 192.168.2.1 and you should be able to ssh to the nook on 192.168.2.2. root has no password. takes a long time to generate ssh keys so be patient.

Sources: XDA-developers (1) (2) via Gizmodo