Here are a few Japanese quizzes to test your kanji and katakana:
http://www.engless.com/sekai/japanese/japanese.php
There are separate quizzes on single kanji, compounds, by kyouiku level, verbs, adjectives, first names, family names etc.
The first level of the katakana quiz is on single characters, the second level, on words in katakana.
(with a bit of practice anyone can do 200 in 30 minutes and score 190/200)
Here are a few more quizzes but with phrases in romaji and kanji:
http://www.engless.com/sekai/japanese/japanese2.php
...relax, they are easier than you might think.
...and if you happen to know itarigo here are a few more:
http://www.engless.com/sekai/itarigo/itarigo.php
There is also some kanji wallpaper for your desktop.
Score well to see the next level and go to the Menu to initialize the score. Have fun.