Record highest cell value

I would like a formula or VBA that will record the highest value of a cell. For example I need B1 to show the highest recorded value of A1.

You could use a circular reference resolved by having a tick in the "Iteration" check box on the "Calculation" tab sheet of the "Options" dialogue (Tools|Options|Calculation|Iteration).
If the formula in B1 is

=IF(A1="Reset","",MAX(A1,B1))

the value in B1 will change only when it is smaller than the value in A1. When A1 changes to a lower value B1 keeps showing the previous largest A1 value.
To restart the process enter "Reset" into A1. B1 then goes blank.

Beaunydal