Detail cameras are great because you can take dozens more photos. We now shot about 150 a day. I rarely delete a signal picture because with software like Microsoft's Digital Image suite, you can make bad pictures look good. Their software is amazing and easy to use.
Here is another idea, on Main Street at the photo center, you can take your memory card and have the contents burned to CD-ROM for about $12. After burned to CD-ROM, you can reformat the memory card. Then take the CD-ROM with you back home.
We did this when we filled up our memory card at the park and didn't want to buy another one.
Another option is to buy another memory card before your trip. Sites like Buy.com have excellent prices and memory card prices keep coming down.
We also had a very high end Epson printer and sold it on ebay because the per picture price was about 50 cents counting the ink and paper. Instead, I now use Ophoto.com or snapfish.com where prints are about 15 cents per print plus shipping. If you want instant results, you can get photos printed at Costco and most drugstores today.