So you renamed all your files with a sequence number, and uploaded them to a gallery... but they are not displaying in the order you want them to... why is that?
Computers look at numbers differently than we do - they see only the first digit and use that to sort by first, then they sort by the next digit and so on. So when a computer sees the following numbers:
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,18,20
It will sort them like this:
1,10,11,12,13,14,15,16,17,18,19,2,20,3,4,5,6,7,8,9
which appears out of order to us, but realizing the computer is merely sorting by the first digit it sees, it makes sense.
So how do you solve this? Very easily... all you need to do is make sure that all numbers have the same number of digits - adding leading zero's in when needed. So in the above example all numbers need to have 2 digits, which would be this:
01,02,03,04,05,06,07,08,09,10,11,12,13,14,15,16,17,18,19,20
So if you have filenames that go from 1 to 1250, all numbers need to have 4 digits, like this:
0001,0002,0003.... 0099,0100,0101,0102.... 0999,1000,1001,1002
The main time you will see this is when posting images to a web gallery. Modern Operating Systems like Windows XP and Mac OSX are smart enough to display numbers the way we expect to see them, but webservers still sort based on the first digit. Thankfully almost all renaming utilities give you the option to specify the number of digits each number will have, which takes care of the problem.