I got a 30 on the ACT... and a 1920 (i think) on the SAT
The ACT is graded on a scale of 1-36.. There are four sections (english, reading, math, and science) which aren't split into 8 or so tests like the SAT. No one really gets below a 10 composite unless you just leave a lot of answers blank (the lowest grade of anyone I know is 14, and that was only one person). I think mostly the ACT is an SAT replacement, a lot of people in the midwest take it in place of the SAT. The percentiles for each composite score is listed here...
http://www.actstudent.org/scores/norms1.html Some people say the ACT is easier (I thought it was), while others say the SAT is easier.