Boot any machine w/ full installed Usb ubuntu?
 

The question is simple. If i do a full install ubuntu on a flash drive, can i boot any machine with that which supports usb boot??? Will it work? Will the drivers cause any problem?
I tried a persistent install but didnt work. Started giving me errors. Thanks in advance.

It depends. Like for example, if you install an x64 version, an i386 machine can't boot it. But if the version you installed is likely to work on a machine, it should work from a USB stick. That's if you are able to set the machine to boot off USB, you can't guarantee that you can reboot any machine however you like and set the boot order to whatever you want.

So I would say, "probably will work, if you're careful and you think about it".