The good folks at BrianSell.net have produced a great 4 page summary outlining the differences between SugarCRM and Salesforce.com.
Everything from price to data management and backup.
Here is a snippet, but you’ll have to go through their registration to download the whitepaper.
Too bad this isn’t an iPhone app.

Thanks for the post guys! Funny thing, a big part of our services are now migrating companies OFF of Salesforce and ON to Sugar. The price is a big factor in those decisions, and the functionality is very similar.
@Sonja, it all comes down to functionality and price!