The following questions are taken from:
http://www.euronet.nl/~mjkbeeld/Upside-Down_Brilliance.pdf (Credit to Aspi-rant for finding the test)
Tally how many questions you answer YES:
1. Do you think mainly in pictures instead of in words?
2. Do you know things without being able to explain how or why?
3. Do you solve problems in unusual ways?
4. Do you have a vivid imagination?
5. Do you remember what you see and forget what you hear?
6. Are you terrible at spelling?
7. Can you visualize objects from different perspectives?
8. Are you organizationally impaired?
9. Do you often lose track of time?
10. Would you rather read a map than follow verbal directions?
11. Do you remember how to get to places you visited only once?
12. Is your handwriting difficult for others to read?
13. Can you feel what others are feeling?
14. Are you musically, artistically, or mechanically inclined?
15. Do you know more than others think you know?
16. Do you hate speaking in front of a group?
17. Did you feel smarter as you got older?
18. Are you addicted to your computer?
If you answered yes to 10 or more of the above questions, you are very likely to be a visual-spatial learner.
(For the record I am very visual-spatial and got 17 / 18 yes)
I don't know how to answer a lot of these questions. I don't know if I think in pictures or words. I don't think it's either. Maybe a little of both, and also something else, which is neither one. There were only a few questions that I really felt like I could answer at all.