Make your USB flash drives read only, even providing a public folder, with Elgindy USB Protector
Elgindy USB Protector is a free utility that lets you secure your removable drives by making their contents “read only” — no one will be able to delete, modify or even add new files in your drives, unless you provide also some public folder that the program is also able to create.
The interface is not exciting, but it is as simple as it can be, you won’t face any problems using Elgindy USB Protector. Just choose what you prefer and activate this option.
Note that you don’t have to (although the program can) format your drive. Just don’t forget that after you protect your USB drives only on your own computer you will be able to use your drives with full control of them; the same drives on a different computer will be locked for modifications.
An annoying feature is that Elgindy USB Protector forces you to visit its web site when it runs, to check this way for updates.