I'm not sure what program you are using but I'm going to assume you dont have photoshop or paintshop. I know ms paint comes with all window assuming you are on a windows machine. Open the image in paint. Go to Image -> stretch/skew. Put in new horizontal and vertical percentages and click ok. Now File -> Save as. Make sure to save as a .jpeg and not a .bmp
That should work for you. If you have photoshop or paintshop pro there are better ways to go about this so let me know.
i was wondering the same, can anyone tell me the right way to do it in photoshop or adobe elements? every time i do it the file size doesn't seem to change.