ereg_replace

I need a little help with the ereg_replace function. I have the following code: $text = ereg_replace("[[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/]","<a href=\"\\0 \">\\0</a>", $text); which pads a url with an href tag to make it clickable. Here's what I would like to do: In the case of the url ending with .gif or .jpg, I would like to pad it with an img src tag instead, so it shows up as an actual picture. Does anyone know how I can modify the above code to do this? Thanks in advance. Mitch