I'm looking for...X

I recall reading about a product that could cause transparent proxies to list an ip that isn't yours.
Someone posted something about it here, and I even downloaded the application. But I never installed it, and it appears as though I've deleted it.
I remember it was some sort of shareware. The site and docs made me think its from an individual developer.
I've looked back through the last few months and I can't seem to find the tread it was in.
Anyone know what app I'm talking about?