http://www.nytimes.com/2010/06/07/technology/07brain.html I tried both of their tests ... the "focus" test seems to indicate that I am a very low multi-tasker (for both two distractions and six distractions I got a score of 2) while the "juggling" test seems to indicate that I am a very high multi-tasker (my times for "switching between tasks" and "repeating tasks" were as long as or longer than the high multi-taskers ... for some reason my "additional time for switching" was negative).
I think what this really indicates is that I am much better with shapes/colors than with letters/numbers.