Has anyone tested any of these iPhone GPS based Apps? They could be a pretty cool and useful for when you gocart, autocross, time trial etc and you don't have a data acquisition system installed.
MAXQDATA (Free)
http://maxqdata.com/iphone/MaxQData/index.html
or iTunes Store: http://itunes.apple.com/us/app/maxqdata/id344711138?mt=8
LAP TIMER 1.1 & LAP VIEWER ($11.99)
http://www.firstclass.com/~ron/Lap_Timer/Main.html
or iTunes Store: http://itunes.apple.com/us/app/lap-timer-data-acquisition/id314138229?mt=8
db Meter ($0.99)
http://www.faberacoustical.com/products/iphone/db/
or iTunes Store:http://itunes.apple.com/us/app/db/id303365575?mt=8