Nick Gammon in his Arduino power saving tome mentions that the TV B-gone product does the various IR controls, and then puts itself to deep sleep, and the button you press is the reset button which powers it back on. Now this will use some amount of power even when it is sleeping, but in the grand scheme of things, it may be enough for your purposes. Here is the article: http://www.gammon.com.au/forum/?id=11497
Here is the TV-B-Gone kit that ladyada sells, but I'm not sure if the source is available: TV-B-Gone Kit - DIY Universal Remote