This page simply validates linear units of measure.
I built it to test my sanitizion, validation & conversion code.
Similar to latitude and longitude, I want to:
Trim whitespace; Strip slashes; Convert HTML special characters.
Allow negatives (for now).
Trim leading zeros: "-005.5" --> "-5.5".
Round to three places past the decimal
Begin with zero: ".6" --> "0.6".
Correct negative zero: "-0" --> "0".
Accept floating point values less than the diameter of Earth (12,742 km)