well first of all i wanted to know if there is a program that cleans my contacts? for example, i have 150 contacts on my phone but when i connect the phone with my MSN IM. i have 500 contacts which is all over the place... is there a program that can separate the msn contacts with the phone contacts?
if not, could this be a nice program to develop??

You can seperate (temporarly) your contacts by hitting "All contacts" at the top bar and then click "Groups" and select MSN.

That filters.

You can filter contacts by groups

I know not really what you are looking for, but it might help

Whil I am at work on our own jabber server, i usually filter by that group so I only see them

well filtering them sometimes creates an error T.T
well i guess.. filterin them is the only solution for now

I think what he is wanting is something that goes through the 500 contacts and identifies all of the potential duplicates (or same contact from different sources) and automatically merges them.

I would find an application like that to be very handy.