on the subject of trays, we had a load of chinese take-aways just the other day. the plastic trays seem ideal as seed trys. i will line them with some black bin liner though, so that the emerging roots wont be able to see the light ;) and some drainage holes, of course
on a related matter, my mother has for years used yoghurt pots for seeds and first planting on of tomatoes, for instance.
seems to work fine too. make holes in the bottom for drainage, is all.
i have a hole pile of recyclables waiting for potting compost and seeds now :D
svea