http://darkwing.uoregon.edu/~leslieob/pizzaz.html : People Interested in Zippy and ZAny Zcribbling
Although set up for beginner through advanced ESL students, many of these ideas can also be used for ABE/GED students as well. I liked the writing activities in the section called 'Writing Roulette'. There are also some lesson plans, which all instructors love.