Popped on 7th Sept.
Ski here's my thoughts on weaning (although I was bought a weaning recipe book by other mothers concerned I was going to kill DD!) Well known fact that breast milk is the most calorific foodstuff you can cram into babies. Formula is designed to be as close as poss to BM, so is bound to also be calorific. Tiny guts not really designed to consume much else for months. Giving them some kind of solids early on will fill their stomachs temporarily, but won't satisfy them for long, as they can't get much out of it. Also - have you tasted baby rice? 
I went for baby led weaning, which advocates that if a baby can pick it up and get it into it's mouth, they are developed enough to eat it. So, theoretically, if your baby can use complex tools they could be eating lobster before you know it
. In a more basic form, though, it means plonking a lump of something on the tray in front of da baybee and letting them figure it out for themselves. They can manage fist size bits of food like rice crackers with Philly on them (or frigging dellas, whatever the Dutch equivalent is,) quite early on, and watching them practice their pincer grip on peas is hilarious.
I started DD on solids when she smacked her hand into my Christmas dinner and started licking the carrot mash off it. She was 5 and a half months. They start getting REALLY interested in food and what you are eating when they are ready, and start trying to steal your grub. The advantage of BLW is they can eat whatever you are having, and you can polish it off if they don't eat it. None of this is to say you can't buy baby convenience food too. But you don't want to end up with an 18 month old that will only eat Cow and Gate slop. (Ella's Kitchen pouches are really handy though!)
One thing to bear in mind is weaning is really messy, and once you've started you can't really go back. Milk is just so much easier!
Silver if you want a bit of inducing Boxy-stylee I will be bouncing round forests in the 4x4 tomorrow 8am, hoping to catch glimpses of the racehorse following hounds. Will understand if you want to sit blimp-like on the sofa stuffing your face with chocolate though!