Time is an illusion, lunchtime doubly so. That was Douglas Adams' way of putting it. Still, when that hour rolls around, it's time to go do something.
I like to get out of the office, even if it's only long enough to go pick up food from somewhere. Perhaps I'll eat out, sitting in a cafe or restaurant with a magazine (or the Kindle), eating and riding. Sometimes I'll meet someone for lunch, but usually I am happy with my own company.
Sometimes I'll bring lunch back to my desk, and bring up a script site, reading TV and movie scripts while I eat. It does seem to be all about reading, though.
I remember, as a kid, I would not be able to settle down with a sandwich unless I had a comic to read at the same time. It was almost always a copy of 2000AD, the British Science Fiction comic that I read for over twenty years (right from the first issue). Sometimes I'd be happy with a novel or something factual, as long as it was interesting.
These days, with things like YouTube and Hulu, it might be tempting to catch up with TV shows, but I find that I usually don't do that.
What I should be doing is writing. Blog entries, for example. Huh. Look at that.