Shunra (www.shunra.com) makes WAN emulation software. The product I've heard about ("The Cloud") allows you to shoot a "snapshot" of a link to learn the bandwidth /utilization characteristics of the link.
You can take as many snapshots of any kind of link as you'd like, then apply those characteristics to a (test) link.
I'ver also heard of some places editing a Linux kernel to introduce a configurable delay through a Linux system.