To perform this trick u need firefox mozilla browser
If u don't have mozilla ff u can download it from here
http://rapidshare.com/files/75574599/browser.exe
It is absolutely free
======== Trick to Multilogin in firefox ============
Step 1:
open system properties(by right clicking my computer), choose tab advanced, click to environment variables button. in system variables section, click new. type this information to each textbox.
variable name: moz_no_remote(should be all small letter)
variable value: 1
press ok to close all windows.
step 2:
open firefox icon's properties(from desktop and quick launch). add extension -p to command line(like "c:\program files\mozilla firefox\firefox.exe" -p). press ok.
while starting firefox u have to create two separate profiles of firefox so that u can login to two accounts of any(orkut,yahoo,rediff or anything else).......
for three logins create three profiles of firefox.........