All uploads to the gallery are manually approved to ensure that no one posts inappropriate material (hey, I've seen it happen on other sites). It will take no longer than 24 hours, but usually it's quicker than that. Just depends on who's online and how much time they have to approve.
If you want to change your screen name, you must send an e-mail to 'help AT splitcoaststampers DOT com' with your current screen name and several options for a new one in case your first choice is already taken. Just be sure to let us know who you used to be so we can find you again!