My 3.1 DD seemed to be very keen on learning letters, words etc and I went as far as asking advice on MN, buying a few workbooks and asking the schools what phonics programmes they use.
Then decided that I was being crazy - she's got a good 14 years + of schooling ahead, we're hoping to aim her at the London super-selectives at 11+ so probably some pretty intensive study as well. Why rush it?
So we have no fridge letters or numbers, I put the workbooks in a cupboard and we do other things - visits to museums, collecting pine-cones and leaves in the woods and making things with them, visits to playgrounds, dolly tea-parties and so on. We do read a lot of books together but concentrate on the story not letters or words. There really are masses of things you can do with bright kids that don't involve any kind of formal learning.
She goes to a private nursery 3 days a week (9-4) and I chose one that does almost entirely free-play. She loves it and is super-excited about going to a more formal learning nursery school in September.
She's a bright kid and I know she would happily learn to read etc if I encouraged it. I'd rather she went to school knowing nothing and got excited about it all being new and fun rather than BTDT. She can count to 20 and count out objects/stairs, can recognise her name, sing the ABC song, knows a gazillion nursery rhymes, can put her clothes on and off, can use a knife and fork and she has decided to swap the nappy for knickers 3 weeks ago, so I reckon we are good to go.
FWIW, I went to hot-housing preps as did my siblings and it made zero difference if you could read before you went or not, we all did by the end of the first year.