Transwikia is a service that aims to make translation far easier and more interesting.
No need to translate every sentence yourself, though you can do it by making the page 'private', but The advantage of making the page public is that others can also translate, rate the best translations and earn points which will make translation even faster and collaborative.
Once you translate any sentence or add any page you will earn points that indicate your level. Both your earned points and level are shown in your profile page.
Now you can start translating (or playing) adding new pages, or clicking on "Community" tab shown in the top bar to see latest added pages. If you added a page yourself, you will find the final page that contains all translations (ready for copy-paste) in "my pages" tab. You copy the text out there and paste it on Wikipedia considering the wiki format. Currently we have no direct contact with Wikipedia.