previously mentioned the Topfield 5800 digital video recorder, affectionately known as the Toppy, though I've never got round to a full review (a summary of its good points is in this post: twin tuners, Freeview, Top Up TV-ready). In my book it's the best hard drive DVR around, particularly for geeks who like writing their own programs (called TAPs) to get it to do stuff - I'm on my second bigger one (though there's something buggy with it or the firmware, I've not figured it out yet - it keeps crashing unpredictably and I've lost recordings, but the previous one was perfect).
Well now the excellent user site Toppy.org.uk is running a contest where two TF5800 PVRs with 250Gb hard drives, one Black Panther and one original silver edition, donated by Topfield's UK distributor Turbosat, are up for grabs. It'll be more of a prize draw I think, as the answer to the competition question is easy if you scan the Toppy site or indeed (and probably that'll be quicker) my own blog posts about the Toppy.
The deadline is midnight 17 December. You can enter as many times as you like, by postcard or by SMS text (£1.50 per text plus any fees charged by your network provider, via your mobile phone bill) but you can feel virtuous as the fee will go towards the running costs of the site, which is well worth supporting, and a donation to the World Food Programme. I should add that I am generally wary of sending texts to strangers because I don't want big charges or mobile marketing texts thereafter (with my mobile number being added to some list for mobile spam from advertising, marketing or PR companies), but I've donated by text to Toppy.org.uk before and never got charged anything other than what I expected, nor have I ever got any text spam as a result.
Here are the competition entry details. Good luck!