1. Find an MSN messengers contact IP address
This will only works if you sending them a file e.g photo, video, etc and doing a peer-to-peer connection while they are downloading it. While sending them files, ensure you have DOS Prompt opened (start > programs > MS-DOS Prompt) and type in: netstat
You will then see a list of IP in the DOS Prompt of all the connections, one of them must be from your friend which is receiving the files from you.
2. Find an IP though mIRC chat channels
Lots of nickname are in IRC but some people use proxies or shells to protect their real IP address, how to know if the user uses web-shell or a proxy is by using tools such as IRC Scanner v1.0 to scan the IP users in IRC channels.
3. Get your friends IP address by sending them to your page
Make a simple site in geocities or anywhere else , then go to http://www.stats4all.com and create an account , they provides free website statistics , add their code to your site and tell your friend to check out a cool page that you just made, so whenever they are visiting your page, their IP will be recorded in stats4all.com so after your friend visiting your page, check your stats in stats4all.com and you will find the last 5 visitors at the left of the stats page .