Yes, I know wiki has a long time back made all the links nofollow but the links still have lot of value in terms of traffic. If you can manage one link from wiki, it will give you very good traffic. Since the same External links many times are used in other language wiki’s too, so a good chance of getting more traffic from them too. While editing wiki pages and putting your links there, make sure you are not putting a low quality link (they will get removed in no time). Put a Good content link, may be specifically made for wikipedia with no ads on it.

Tip – Instead of directly linking to your site, try to link to your ezine article or better to your squidoo article (which gives better control to you). Once you get the link, you can change the squidoo content/links structure a little to take better leverage.

Tip2 – Don’t cross the line. I have seen many people doing this and getting traffic hence putting it here but if you over do it, you will harm yourself, All your links will be removed, your account will get banned and possibly your site too.