Hi AMS,
Yes, you guessed it, standbys are BORING! You report at Compass and wait....and wait....and wait. Fortunately there are things you can do...meet up & chat with your colleagues (after a while you'll start bumping into familiar faces more & more), chill out at the cafe (or 'singles bar'...whatever!), have some grub in the canteen, read gossip mags & horoscopes, watch TV in the TV room, sleep in the quiet room, bring a DVD player.....whatever.
There's no getting away from the fact that it is not really a very enjoyable experience. Hopefully you'll not have more than 1 a month.
By the way, I'd just like to point out the fact that although the above BA shorthaul roster looks busy, it is NOT! There are nightstops included if you look carefully....apart from that, BA shorthaul is just about the easiest flying available at the moment....I worked for a low-cost airline and believe me, BA is a walk in the park (at the moment, and only at LHR!)