Transfer Speeds across WAN

Anyone aware of a nice free utility (for Windows) that will check transfer speeds from Destination A to Dest. B? I'm looking to transfer up to 2.5GB across my WAN on varying WAN connections with other data. I'm looking for something that can run a test for me. I'm basically looking to see when things are going to bog down.. it would be nice if I could run it throughout the day to watch for a network bog down or spikes.. but that's getting up there. I just need something that will tell me what kind of transfer speeds I can expect over anywhere from a 5 minute to couple hours of transferring.
I'm doing a google search in the mean time, but I'm really looking for someone to say "use this program, it's nice" instead of screwing around with the first 20 I find off google.


Riser