Here's a tip for anyone running Windows Vista Home Premium or Ultimate editions (the ones with Media Center functionality), if you have a suitable tuner set up and configured. I mentioned this in passing to someone who uses Media Center as their primary TV tuner, and they didn't know it was possible - largely because it's a bit obscure and not exactly easy to find.
I don't use Media Center as my primary TV - we have a Sky HD box to do that, and although I'm generally happy with the functionality and reliability of the Sky box, its UI isn't anywhere near as flexible as MC's. The Guide is one example of that - Sky lets you browse the guide but the options to search it are a bit thin, so it's OK if you know there's something you want to record. MC allows you to query the schedules (including all the obscure channels you might never watch) to find specific named programs, or even ones where the metadata matches your search.
My PC in the study has a cheap Hauppauge USB Freeview tuner installed, and an XBox 360 in the living room allows us to watch stuff that gets recorded on the PC.
If you go to Recorded TV on the main MC menu, and select to Add a Recording, you get:
... meaning, you can record something based on searching the Guide. If you choose the "Create a custom recording" feature, however, you can have MC automatically record a programme that isn't scheduled yet, on the off-chance that it will be shown again at some point. Useful for catching up with old films that appear every few months.
In this example, maybe I want to record Ghostbusters. Select Keyword from the custom list:
Now, selecting any of the first 4 options will search against the current guide, and if there's nothing scheduled, you won't be able to select it. If you pick Generic keyword, however, and you get a slightly different UI:
Media Center will allow you to save your query, and will record anything that shows up in the guide at some future date, which features the word you just entered..
If you want to check what custom recordings you have scheduled, start again from "Recorded TV", and select "View scheduled" - you'll see a list of anything that's set to record, but only if it exists already in the guide.
As I said, not exactly obvious... but very cool!