I was just about to start a similar thread when I saw yours. I will be trying to bring a desktop and a 24" widescreen LCD from the US to Colombia. So far I have called both the TSA and the airline several times for clarification. The particular airline (Delta) has a policy of no laptops or desktop computers in checked luggage. Note that this is not merely a denial of any liability for it being lost/damaged/stolen. I am not sure what they do to enforce this however.

I have decided to buy a special carry-on bag just to hold my new 24" LCD and the innards of my desktop computer. I have found it impossible to find any baggage/travel insurance in my case because my length of stay will be 1+ years. In fact I can't even get computer insurance from places like safeware since Colombia is on the list of countries with travel warnings on the US Dept of State web site.

From what I can gather from the TSA hotline, computers, computer parts, and computer monitors are all allowed through security and there should not be any issues. Nevertheless, I am putting in place a plan in case I am denied entry with my computer parts. I was told that the whole thing about having to turn on all electronic devices is not actually set in stone. If it were no one would even be able to travel with hard drives since those cannot be turned on or even really inspected without damaging them. However, *everything* is at the discretion of the TSA officer. They do not need a good reason or even any reason at all to deny you or anything you are carrying entry past the checkpoint. So there is certainly an element of chance involved.

For this reason I am planning to arrive at the airport about 5 hours before my flight (although the TSA may actually find that even more suspicious, but you can't win with them), so that I might have time to leave the airport and repack my monitor and computer parts in a larger suitcase to be checked as an additional bag if necessary. This would cost an extra $125 with Delta, unless I could manage to convince them that it wasn't my fault, but the fault of the TSA for being so unpredictable and arbitrary.

Also don't forget about customs in your arrival country. Even a very small desktop like a Shuttle SFF will likely not be seen exactly the same as a laptop. A SFF or uATX case may not be afforded the same privileged duty-free status that laptops enjoy. It could also bring into question your visa status in certain countries. After all, why would any sort of tourist or temporary visa holder need to bring a desktop? I suspect that it will be looked at with suspicion in such cases. For a business or immigrant visa OTOH, it would probably be okay.