Many firms have used the Riverbed network acceleration hardware when they have offices in multiple locations. Do anybody out here has had first hand experience with these products?

Please be aware that increasing the 'pipe' size will not necessarily give the performance boost you are looking for. It will heavily depend on the physical distance between the two sites. Distance is the main contributer to latency (or network delay).

The greater the delay, the more likely that a WAN link will be limited in real throughput not by the pipe size - at which point bigger pipes will make NO difference to a single users experience. This is not to say that bigger pipes are not useful, particularly when you need more users using that link at the same time.

And this leads to WAN optimizers, there primary purpose being to significantly reduce the effect of latency and also reduce the data traveling over the link.

If you really need to speed things up, you might want to go for T3 (44Mbps). Not sure of the cost difference, but time is money.

Do you want to say that I must have adequate "thick" WAN lines? or what...?

Working on similar Applications.