EDIT: The ClamWin people have fixed it, so you can disregard this topic now 
This app looked like a good idea, however I receive many false positives while scanning.
For example:
F:/PortableClamWin/PortableClamWin.exe: Trojan.Clicker.VB-20 FOUND
F:/PortableFileZilla/PortableFileZilla.exe: Trojan.Clicker.VB-20 FOUND
F:/PortableThunderbird/PortableThunderbird.exe: Trojan.Clicker.VB-20 FOUND
I saw on the PCW page that there is a known issue for a false positive, but if this is a regular thing I'm not sure I can trust it. Still going to keep it around though.