ok, here is a tennis game with a realistic game play. The controls are quiet complex but if u play long enough u get the hang of it. A real tennis fan like me would apreciate it.
Moving: J, K, I, L
Hitting ball: A,S,D (forehand is when the ball hits yo rocket when u begin yo swing, backhand is when u end yo swing. A is shortest, D is the longets hit)
Serving/receive serve: H
Switching rockets: Space Bar
screen:      http://img458.imageshack.us/img458/4599/screenbj3.gif
download: http://www.4shared.com/file/15043646/a1dfb8e1/tennis1.html
applet resolution:  1000 x 700

EDIT: forgot to tell u: the blue circle marks the quadrant where u should serve or where the opponent will serve. if u press H and nothing happens u should move behind the baseline or to the opposite side of the serving quadrant (or u could read about tennis rules on the internet).

that's great

thanx for the reply. I knew somebody would like it.
New update:
http://www.4shared.com/file/15531405/17da7d19/tennis1.html
Changes:
An ugly setting window where u can change the strength of yo opponent, gamespeed, and surface. (ball bounces differently on different surfaces).
Added webpage to run the applet. 

My ugly source code:
http://www.4shared.com/file/15532261/50d5cdda/tennis1.html