Riverbed optimizes Microsoft SharePoint Services to deliver LAN-like performance for remote offices by simultaneously addressing bandwidth constraints and the combined effects of latency and protocol inefficiencies. Have a look at the Performance Benefits in the following document:

http://www.riverbed.com/microsoft/media/docs/PerformanceBrief-Riverbed-MSSharePoint.pdf

Book now for the European SharePoint Conference in Berlin from the 17th-20th October.