Go with myphone. in my opinion its the best program to back up contacts, among several other things.
I also used to use PIM Backup but after 6.5 came out I started having some weird issues with it.
If your still on 6.1 just use your phones browser and go to-->
http://sn1-p1.myphone.microsoft.com/...t.po?mkt=en-US
is so easy and works awesome~!