why is it so damn hard to find a job?

[Jimbo]

Couple thoughts. I've always believed you stand a better chance if you "flood the market" in whatever field it is you want to be employed in. By that, I mean in a given geographic area in which you'd like to work (say a 50 mile radius to start), do your homework and find out every company there that in some way does whatever it is you want to do, and whether it requires a resume or an application, apply at every single one. And don't judge them too harshly before you say, "No I couldn't work there", you need to get your foot in the door and get some experience then you can look elsewhere.
You mentioned you worked at UPS through a temp agency and seemed to enjoy it. Get on line or get out the Yellow Pages and copy down the name of every single company that does courier or delivery services. Create a resume and make sure you include the temp agency on it under experience and references. Also, don't forget to contact the USPS.
Above all else try not to let yourself get discouraged. You'll find something.