How do you encourage an intelligent child?

Hey all,
My daughter is one i would consider pretty switched on, she was 2 on Friday (June 6th) & is pretty cluey about a lot of things. I can only compare her to friends & family around the same age but she seems to be a fair bit ahead of them. This includes things like walking, talking as well as picking up new things on a daily basis. She's also has excellent manners!She can tell the difference between cars, trucks & trains, she knows a HUGE number of animals when she sees them & for many of them she knows the sounds they make as well.
She loves to read her books, dance (she knows a lot of kids dances by heart), sing (she cant always get the words out but she knows the tunes), she'll draw a lot & loves to interact with her Fisher Price Little People play sets (these have been the best thing we've bought her so far i think) - she has an excellent imagination - she makes the farmer walk the cow, she makes him feed the horses etc. Her memory is excellent with people & other things, she is always asking questions & strings along words in a sentence without any trouble.
This morning she shocked me, while i was making coffee - waiting on her toast to pop up, she started to count. At 18 months she could count to 3 & then not long after she got to 5 but this morning she counted all the way up to 10 without any help or getting numbers in the wrong order. She has cousins that are a year or so older than she is but even they cant get that far.
If you have a child that you consider more switched on than others of the same age - or maybe even older, how do you help to encourage them to keep on learning? Are there any toys or games or anything that help you get them to continue learning at the pace they have been?
Thank you for your thoughts!