Scoring

MatchTuff EZ-Score
A portable scoring system.
http://www.matchtuff.com/

Nosava Sports Scoring Systems
Available for tennis and swimming available with a digitized photo.
http://www.geocities.com/nosava_1999/

Score-Sticker
Sells a sticker to keep personal score -keeping on a racquet.
http://www.score-sticker.com