Thanks for all of the kind comments. These are my growing conditions:
B. liniflora- I cannot add anything useful to what Dewy said, except maybe that they don't seem to do too well grown too close to the lights.
B. gigantea- I received the plants as seedlings a couple of cm high. They are in a mix of sand, peat and perlite on a South facing windowsill in 6 inch pots. I stand them in a couple of mm of water, and top it up a few days after it dries up. They grow really fast. As I said, they were about 2cm high in March and the largest now is around 18 inches tall. I have no experience of overwintering them. Although I have never grown B. gigantea from seed, I have recently managed to germinate one Byblis lamelleta seed. I soaked around 8 seeds in gibberelic acid for 2 days and then sowed in my terrarium under lights. The first one germinated about a week ago. I have been told that it is best to germinate B. gigantea & lamelleta seeds in terraria and then move them to somewhere cooler and less humid once they are seedlings. Interestingly, I have noticed that, despite doubts over the carnivory of Byblis, my B. gigantea plants produce clear juices that can be seen dripping down the leaves if they catch a reasonable sized insect or are given a tiny bit of cheese. Whether enzymes are present in the juices I cannot say, but I find it odd that the plant would do this if it served no purpose.
Drosophyllum- I received the photographed plant as a seedling in June 2004 in a tiny peat pot. I Slack-potted it in two clay pots using a mix of sand, peat and John Innes. I water it via the top of the outer pot every few days in summer and every week to 10 days in winter. The surface of the inner pot is always bone dry. The plant flowered last April, and I now have a couple of seedlings growing. I sowed about 7 seeds in July. I scratched the surface off a few of them and sowed the rest untreated, although I don't know which germinated as I stupidly mixed them all together. The plant produced around 30 seeds, but unfortunately my girlfriend mistakenly threw the spare ones away. I was planning to give them away on CPUK (as I am based in the UK). I keep the Drosophyllum on a sunny windowsill which is cool in winter. Its growth slows down in winter but there seems to be no real dormancy period. I hope this helps.
Greg.