In July 2004 I released a modem emulator (a.k.a. a throughput throttling proxy). It was created to help give designers a sense of how their sites function for people with slower connections.
I've had to take it offline a number of times due to the volume of traffic and the various ways it was being used (turns out it was a highly effective way to bypass workplace web filters).
Not only that, the code was badly out of date (code soup, not an object in sight, no real validation ... the shame) and badly needed an update.
It's been sitting there, half-working and half-not, and begging for an update for almost exactly 4 years. Ultimately, the choice was to update it or kill it permanently.
So, I spent some quality time rewriting the whole thing, pretty much from the ground up, and now with pleasure announce that it has been turned into an open source project (yes, another one) and the code is now available from Google Code under a New BSD License.
With any luck, this will allow more people to make this tool part of their workflow.