I would suggest that you tactfully point out the typos. I have done this several times for both clients and potential clients and have always received a positive response welcoming the input. If there are numerous typos I usually point out one or two and then suggest to the client that, for their benefit and in order to appear as professional as possible and for a small fee, you may review their site for any other errors. You could also just do it for free, something I have also done. The important thing to remember is to do it in a positive manner and in such a way as to not offend them.