I have used a spreadsheet on my palm computer to make finding mile splits easier.
I made a simple spreadsheet that calculates the JO counts corresponding to mile 1, mile 2, etc. The spreadsheet is designed on my "real" computer and tranferred to the palm. From there, I only have to enter five counts from the cal course (beginning, end, each turn-around) and the count at the beginning of the course. Not that these numbers were that hard to determine, but I think this makes it a little easier.
Afterwards, I enter the five counts from the post cal and it bases the course length on the constant for the day.
I should mention that so far, I have only used this to measure my own training loops. In other words, I don't adjust the course length. I suspect the spreadsheet could be adjusted to account for that.
I would be happy to share the spreadsheet with anyone who is interested.
I don't know how helpful this is, but I thought I should share it in case Pete follows through on his threat to pull the plug!