If there is one piece of advice I would recommend to everyone is never go anywhere without a decent camera. When the voice pops into your head that says 'I won't need it, I'm only going to the shops/pub/put for a moment,' ignore it, or better yet overrule it. The opportunities for photos is practically infinite and I only regret not taking the photos I wished I had.
If your main camera is too big to carry all the time, go smaller and get a compact for emergencies. Last night I was out in the countryside trying to get a good sunset. I got a couple of OK shots but nothing great. Tonight I decided to go out for a meal without my camera and to my dismay the whole sky was filled with flaming whisps of red cloud on a perfect turquoise that faded into a light yellow below. Such moments are never repeated again exactly the same way, so I will suffer the extra baggage for the chance of the right photo in future!