Flycast,
SID's are good to use when a user's browser is set to deny cookies...
If you disabled cookies on your own browser, the SID's would then append to the URL in your address bar.
Is it safe to use 'cookies' to keep track of a user's activity when using sessions.
This simply means that rather than appending the SID to each and every session enabled page, you will do a check to see if a session is set at the top of every page...
Check out
SESSIONS
for some in-depth info. on sessions...
Good luck, Mike