Wrapping Text

Hi PHP digest readers. Ok I have a problem and a question which I am certain many share and even a solution to my problem, however I wish to hear how you dealt with this issue to see if there is a better method. Ok for my problem, it is regarding a smilie system. Currently what happens is if people post :P:P:P:P:P:P etc.. etc.. then the text field expands to an ugly length. My current solution which I don't really like is to limit the number of smiles which a person is allowed to use. Can anyone propose a better solution than this? i.e. wrap them using PHP or maybe I coded my html poorly which is why my table is expanding? Secondly my question on a similar note whether to convert smilies at runtime, or when a person submits a post? The beneifits at runtime is less space used in the DB, and no worring about converting the converted post back when it is needed to be edited, however with this method the server has to do more processing in converting smilies each time the post is viewed and vise versa. Thanks for your time, and I anticipate any light which can be shed on this issue. Scott