[Wlug] tmpfs

When researching the Reiserfs a while back, I discovered the tmpfs file system and the --bind option to mount. Both of these are nice tools to have around. --bind has made it into the mount man page, but the tmpfs is not documented in the man pages anywhere I can think to look. Does anyone know of a reason that it should not be used? I'm thinking of using it for some locking files and pid stamps -- all stuff that should not persist across a reboot. TIA, Bill