stajer - 9:48 pm on Jul 25, 2011 (gmt 0)
Don't do it that way.
1. Store the lat/long of the original piece of data in the table.
2. Google for the formula to calculate distances between lat/long coordinates.
3. When you need to find other pieces of data within x miles, use the formula from #2 to calculate the outside lat/long of those X miles from the original piece of data.
4. query your db for other pieces of data between the lat/long you calculated.