I haven't done it myself, but based on talking to a few of my friends that have, most agree it's an interesting idea, but that it wasn't really worth all the ti

I haven't done it myself, but based on talking to a few of my friends that have, most agree it's an interesting idea, but that it wasn't really worth all the time it took, as it didn't really teach them all that much more than they already knew. Granted, this comes from people that have a fairly solid Linux background and typically run distros closer to LFS than Ubuntu (think Gentoo and the like), so depending on your back ground, your mileage may vary. Personally, I'm still interested in taking some time to do it, and I've actually been trying to convince some friends of mine to spend a weekend, with each of getting a system hacked together. There appears to be lots of interest, but getting everyone to agree on a time might just be impossible. Perhaps I'll dig that project out of the closet this weekend and get it done myself... In any case, if you're looking to understand Linux better, it will probably help, but I would suggest that there are probably better avenues for learning it. Advanced Programming in the Unix Environment will teach you all the subsystems you have to interact with (albeit, typically from a programming view), and Understanding the Linux Kernel will teach you the ins and outs of the kernel like nothing else. There may be better books out there for what you're looking for, but those two I have direct experience and would highly recommend. On the other hand, if this is something you're interested in doing, shouldn't that be reason enough? You'll likely learn something on the journey, though it may not necessarily be Linux-related, and you'll be doing something you want to be doing.