ok im not advertising for Wowscape, now they made a nice tool if your tired of going into your realmlist file to change it for private server users. Since i constantly go from Retail
WoW to private servers I use the Wowscape browser. You put in the server IP adress then give it a name the pick it and hit lauch
WoW and Bam it changes yuor realmlist for you. Its a handy tool.
You can DL it from their site
WoWscape :: #1 World of Warcraft Private Server just scroll down the page and its there. It saves a LOT of time.