Gary,
You'll want to use the $fp = file(strFileName);
This returns an array of the lines in the file. You can then use count($fp) to get the total number of lines (records) in the file.
for ($i=(count($fp)-1); $i>=((count($fp)-1) - 10); $i--);
is the loop structure. $fp[$i] should return the line in each loop iteration.
Hope this helps!
Brian Roy