Differences in Time Calculations

[Robman]

I am not sure if this is possible but I can't find a way to use one datetime
field in a record to calculate the time difference from record to record.

Example - A record was created on 4/29/10 08:00 am and another record was
created at 4/30/10 10:00 am - we quickly percieve that the time differnce is
26 hours.

How can I calculate that time diffence in a report? I have tried all kinds
of things but any of the built in functions that I can find like datediff all
require two different fields to calculate agains - in this case their is only
one field that tracks the datetime of the record entry.

My current thinking is somewhat clunky which is to create an additional
field and on creation of a new record map the old datetime (from the last
record) into it and then use datediff on the two fields. I know this will
work but it seems clunky way to accomplish the task.
Any suggestions - searching all of the help files that I could find did not
show me any examples of how I could accomplish this!