Low Power Hardware for a Proxy Machine ?? (Score 1)

I’d like to run Squid as a proxy which has a local hosts which blocks ads. Could someone recommend a low powered Linux based system that I could run 24x7 which could act as a proxy. I don’t any of my machines on 24x7 and although have a few old desktops and laptops which would be suitable, they would suck way too much power. I have a hackintosh on a Samsung NC10 that I was planning on using, however that’s got a 40W power brick. Is there something small, powerful enough to run Squid and not going to add too much to global warming? I hate ads with a vengeance; however don’t want the polar bears to suffer because of this