If you only use contact info in MS Outlook, mobile phone and MSN, then congratulation, you don't have much troubles of accessing all info related to your contacts.
For many people, the info related to their contacts spread through everywhere:
- Business contacts in company's Exchange server
- business Emails, calendar and tasks in company's Exchange server
- Personal contacts in Mozilla Thunderbird
- Personal emails in Thunderbird
- Personal contacts in Thunderbird
- Business contacts and personal contacts in PDA/smart phone.
- Instant messenger conversations through MSN, Yahoo Messenger, Gtalk and ICQ etc.
- Online social networking like Facebook, MySpace and Twitter etc.
- Blogs
- ...
There exist solutions to aggregate these info and use the info. Typical solutions:
- GrandCentral
- Social Network Aggregation like FriendFeed
I am not sure whether there is an aggregation service that aggregate my Email conversations in company's Exchange, my personal pop3 Email account and my Gmail. I would wish similar service occurred in MSN, ICQ and GTalk etc., since I keep multiple online identities for different online social circles, as many of you would. And I sometime just want to have a centralized place to review all conversations in different online social circles.
In addition, we haven't yet dump fax machines. It would be good all fax contents can be stored and indexed in computer.
There are mature solutions for business world, however, what about solutions taking both private world and business world?
Is it technically hard to aggregate all information related to your contacts? I think you would have no doubt that FBI or CIA can establish the whole aggregation of all your communication activities, if you are lucky enough in their watch list. Unfortunately they don't have enough man power and computing power to do the service for everyone, and they won't let the owner of the communication activities to review the aggregation.

