It's a pity Polish parents living abroad so easily forget their mother language and don't teach their children.
On my polish language course at doncaster college we have some older folks near on 50's who had polish father's but they were never taught polish by them and now because they want to communiate with their relatives in poland they are having to learn :)
Teaching is a good starting option
It is if that is the area you would be comfortable in ... me i would love to be able to work/find work within administrative sectors upon my relocation in the future to Poland :) i am registering my details via the local JCP with the EURES section (their site is eures.europa.eu)