I only know of Denmark and Germany but only if you have held them for more than a year I believe.
Does anyone know of any others?
In terms of taxes its complicated to my knowledge, the legal status is still changing.
Assuming standard law tax is only applied if their are gains and at the time of conversion.
Oddly enough bitlegal must have been dead for a while but they used to keep good track of the changes, I guess wiki is now the best bet.
http://en.wikipedia.org/wiki/Legality_of_bitcoin_by_country The bitcoin wiki mentions the process for the USA but not much detail is given on other countries
https://en.bitcoin.it/wiki/Tax_compliance