Rema patch kits (a plastic box with a small tube of glue, sandpaper and 6 or so Rema patches) are available at most bike shops and from Bike Tools Etc. among many on-line dealers. You can also buy them in boxes of 100 for shop use or sharing with friends.

Here is Bike Tools Etc.'s web page for the Rema kits and the boxes of 100 patches are shown on the second page:

http://www.biketoolsetc.com/index.cgi