I'm the same way - I can see the appeal of a pocket camera, but I just can't go back in image quality. My wife's Canon SD600 is nice, for a small camera, but the photos just can't compare, especially in anything other than bright sunlight.
fuse04, the Pentax DSLRs have become very popular recently for a few reasons... the first is price, they're the most inexpensive DSLRs available. However, the build quality is great (they're often ranked top in ergonomics, they feel as sturdy or more than the comparable Nikons and much sturdier than the Canons, they probably have the best kit lens), the image quality is terrific (they have the same sensors as the Nikons, DPReview recently declared the K100D to have the best image quality of any 6mp DSLR), and they have image stabilization in the body (well, the K100D and K10D do, the K110D doesn't), which means that every lens you buy will be stabilized. This is a huge advantage especially when you read the Canon and Nikon owners spending $1,000+ for their IS lenses! Pentax also has unbeatable backwards compatibility - every Pentax lens works, it's as simple as that. They also have some of the best viewfinders, which is important for manual focusing, and when manually focusing, they'll let you know when you're in focus, even with a 30+ year-old lens.
All the DSLRs are wonderful, but Pentax is really working hard to give the amateur and advanced amateur a camera that does what they want for an affordable price. (The K100D with IS is currently $491.49 after rebate and the K110D without IS is $412 after rebate, both with kit lens. Prices from Beach Camera.) I'm not sure how the prices weigh out in the UK (or if there's a rebate) but I think it'll probably be roughly similar in comparison to the others.
But, with any DSLR, you're really looking at carrying a few lenses if you want to take full advantage of it... but you'll have the potential to take photos that the PnSs just can't do. Only you can decide if the extra work of carrying it around is worth it to you.