Simple web proxy written in ruby. It's a work in progress, currently only handles GET requests, and does not send header information (also no https support). However, it caches all GET requests under 1 MB to temporary files on your machine. Note that the cache is cleared (and files removed) as soon as the program is terminated.
To run the proxy, you will first need to download the PriorityQueue gem (sudo gem install PriorityQueue), since I used someone's prewritten priorityqueue to help decide what to boot out of my cache.
Then, in Firefox, simply go to Edit->Preferences->Advanced->Network->Settings, and select Manual Proxy Configuration with HTTP Proxy: 127.0.0.1, Port: 2347. You can then start my server by running ruby1.9.1 proxy.rb from the command line.
You can specify port and maximum cache size (in MB) via command line arguments: ruby1.9.1 proxy.rb [port] [cache_size]. My proxy should work for all GET requests, and runs with multiple threads for multiple requests (which is a significant speed boost for large pages), but should not handle https, other HTTP verbs (e.g. POST), or cookies correctly.