...just a few minutes of shows? As an example, just the monologue of a talk show, maybe the first 15 minutes?
If not, after I have recorded the entire show, can I keep just the first 15 minutes and 'erase' the part of the show I will not want to watch?
If it's like the one I have (Motorola Moxie), no, you can't set it to record just a portion of the show. You can tell it to begin early or end late, but only by 2 or 3 minutes.
When you're playing it back, just stop watching and fast-forward the recorded parts you're not interest in.