I created an anlaytic snapshot for opportunites in my org, just to learn the process.  I got asked for some data recently that coincided with my snapshot and I thought that was pretty cool.  Setting up a snapshot is not too difficult but there are a few sticking points.

First, follow the official blog guidelines here.

A few notes on snapshots:

1) Pay close attention to lookup relationships- follow the blog.  I tried this on my own and got confused and then annoyed, and then found the blog.

2) Limit of 2000 records.

3) The snapshot mechanism cannot copy records owned by inactive users.  This means if a sales rep is no longer with the company that person’s pipeline should be transfered to an active user before the snapshot is triggered.  For this reason, I recommend the snapshot report include the following filters: a) open opportunities only and b) active users only.