Speed across WAN minimising Issues

I am in the process of moving our servers to a new site. However, many (11?) workers will still remain at this site for up to 1 month.

I am looking for the best way to minimise WAN traffic between sites.

Here are a few of our ideas so far: –
1. Outlook – Work Offline / synch 60 minutes.
2. Profiles – Currently roaming – make local only.
3. No remote internet access allowed.

File Access: –

Now this is the big question – If I enable later on Offline folders I have never been surethat when opening a document if the local cache is being used (changes synchronised later), or if the network file is being opened.

Can anyone answer this or come up with any other ideas for minimising WAN traffic.

The best answers will sharethe points.