These are the cheapest cards SanDisk do, but don't let that put you off, they work faultlessly. I've used their 512Mb and 1Gb versions for thousands of pictures, and they are a steal. Nikon even say in their D40 instructions that you're welcome to use SanDisk cards without affecting their warranty! Unless you need super fast write speeds, get these.
Wasn't sure what to expect from the card as I'd only just been given a Cannon IXUS70 and it had a stingy 32mb card and it only held 17 photo's. This card allows me to hold well over 2000 at the highest resolution so huge amounts of fun to be had on holidays without worrying about having to save them elsewhere or buying another card. Photo quality I guess depends on many things, but for my point and shoot requirements, it's great value for money. Well done to Play.