AVG/Adaware/SpyBot

Forgive me if this has been discussed before, but I am new at this. Is there a way that I can run AVG Antivirus, Adaware, and Spybot from my USB? Quite often my parents or friends get "gunk" on their PC's and ask me to clean/fix it. I though it would be great if I could have these installed and ran from the USB, so I can just scan their drives.

Any help would be appreciated.

Thanks