hey finn-icky,
ICQ is an instant messaging tool. it will tell you whether people are online or not and you can send them messages, either instantly if they are online or delayed if they are offline. it also allows chatting with multiple people, file swapping, etc. there is also yahoo instant messenger, ms netmeeting, msn instant messenger, aol, etc. lot's of different online companies have them but they don't see each other.
now, one word of caution: ICQ sends up a great big flag that you are online. this makes you an easy target for hackers, especially you cable and DSL folks. i strongly recommend to everyone to go visit
www.grc.com. read his story. i had this thing on my PC before i reloaded to win2000. download zone alarm from
www.zonelabs.com. it's very easy to use and will protect you against most everything out there.
i used to run icq, but don't anymore. now i just call up the buddy i used to chat with.