Ever hear of Trillian??????
My Mentor (he calls himself Dreamwalker) suggested this software called Trillian to me. It supports 5 of the most popular IM softwares, Yahoo messenger, AIM, MSN messenger, IRC, and ICQ all with one click of a button. That way you don't have to open all of them and tax your CPU and RAM. I have used it for awhile now and I love it. It lacks some options but overall is great. You can download the .74 free, but I would spend the extra cash and go pro. Anyone who uses more than one IM client should really check it out. Let me know what you think.