DP and I used to work in Spain quite a bit and have designs to move over there one day. DD's 19 months and although she has no contact with any real native Spanish speakers she does watch a LOT of Dora the Explorer. 
To our shock, the other day she was playing with her bricks when she started to count: uno, dos, tres, cuatro, cinco - accent absolutely down pat and I swear I haven't taught her this. (I know a little Spanish but I've never spoken it to her.)
I really want to encourage her and I'm dead jealous of people with bilingual kids - I think it really sets them up for life. Any ideas in terms of classes for toddlers? Any experience of this? I feel like she just needs to be around somebody quite a bit who'll only speak to her in Spanish. Either that or I'm going to have to get better myself!