DSL Embedded :: custimization/other distros

hey i love the idea of the mini os that is embedded. just a few things i want to ask:

are there ways i can add/remove programs from this? i would like a version that only has runlevel 2 for my small usb drive and another one with more programs for my big usb drive. how can i custimize.

and

are there other distros of embedded linux. i have checked google but all the results seem to be weird hardware stuff... are there any other projects similar to this that i can look at?

original here.