Generate random unique IDs

[Steven R]

I need to assign a random but unique ID to each row. The best way I can think of is as described here:
http://forums.mysql.com/read.php?10,205640,205643#msg-205643

I was wondering if that's really the best, most efficient way to do it?
Filling a table with 100 million rows for the 8-digit IDs (0 to 99,999,999) seems demanding. Or is there some other function/trickery within PHP or MySQL that could be used?

Thanks!