Here is a great tool for you to start the process of introducing a computer based activity to your literacy or numeracy tumbles.
The site is called tutpup and it is very easy to set up and administer. You can set up your class with an access code and that code allows the site to administer your class so that you can keep track of your students progress. The site awards Hall of Fame status to students who have answered the most questions in a week. The great thing about this site is that students go head to head with other students in other locations around the world.
The students have to create their own logon, this logon is created using a colour, an animal and a number. So I am green snake 3 on the site and that is also my avatar every time I log on and when I compete against another student. This feature makes this site particularly secure for those who might find students being on line a bit of an issue. It is very easy to set up and I suspect that once you introduce it to your class it will go viral.
Don't forget to post to the wiki if you have used this tool and let us all know what you think.