Consider this use-case:

1. A non-profit with geographically distributed offices around the world
2. Most offices use MS-Outlook to keep their contacts
3. All regional offices have a need for maintaining "lists" or maintain "groups" to invite these contacts to specific events, such as "Media Events" or send out their "Annual Report" to, or even maintain a list of "all PhDs in say environmental sciences" for sending a specific project related commique for
4. All offices have a need to have an updated contact list

Here's a visual representation of the problem statement:

During my consulting work with non-profits i found that this was a big challenge for most non-profits in India, and remains so to date. I assume this would be the case for a lot of non-profits globally as well.

Highrise, SyncAce and MailChimp to solve the problem

Highrise CRM is a really simple software-as-a-service tool to manage Contacts and maintain communication with these contacts in one place. A non-profit should sign-up for an account with Highrise.

SyncAce is a product for syncing Highrise contacts with MS-Outlook. This means that the contacts on a local MS-Outlook can be synced with the Highrise account purchased.

Further, this tool can be purchased and installed at all regional offices under a multi-user setup, thus ensuring that all regions can sync their MS-Outlook with Highrise both ways. One has to be careful, about not over-writing each other's data. I have not tested SyncAce out, but i *assume* it would have built a feature for managing (or preventing) overwrites by the various roles and participants in distributed locations using the tool to sync with Highrise. If they have not, they should (and pay me consulting fee for this adivse ;) ).  

MailChimp is the most beautiful piece of software i have seen for managing lists/groups and sending e-newsletters to their contacts. It syncs seamlessly with Highrise. It even has a desktop tool called "Hairball", which helps to tag a single contact in multiple ways.

Once again, a disclaimer here, that i have not used this combination myself; however, on reading through the features of the products, and having used some of them, i believe this combination can be used effectively by non-profits and other organisations using MS-Outlook to manage their contacts across multiple geographies.