I can, But, 250x250 is really small for a picture so it will look pretty rubbish, also as 250x250 is going to be square and your original picture is probably not square it will squish it in one direction so things might look a little strange.
but if you want to do it.... go here
http://www.picresize.com/
Click browse, select your picture (the jpeg version) then click quick resize just under the browse button. make sure you select custom size and then pixels from both the height and width drop down thingies, put 250 in both height and width and click resize at the bottom of the page, it will take a few seconds then on the next page select save to disk, save it somewhere you can find it and you'll have a 250x250 pixel version of the picture.