I think you can use a cell phone camera to take your own pictures. Quite a few cell phone cameras are very good, if not better, than some "regular" cameras. That said, you also have to make sure you take the right pictures (people don't care what about close ups of your outside flowers or decor in the home) and stage the home for the pictures (toilet lids closed, remove clutter, make it look better than you would for a showing).
I've used my cell phone camera to take pictures of the last two homes we've sold and the realtors used them for the listing. The pictures are just as good, if not better, than many I've seen online. Our most recent home sold in September for over asking price.
Another idea: Take some good outside pictures of your home during different seasons. If you sell your home during the winter, but it looks absolutely stunning during the summer or fall because of the landscaping, it's nice to have one of those pictures to include in the listing so potential buyers can see.