What flash drive is compatible with my old Mac OS X 10.5.8 so I can save the iPhoto photos before I recycle this old Mac? I cannot dind a flashdrive thats compatible with this old version. I am not tech savvy. If not by flash drive, how can I?

Quite literally, any flash drive will do, as long as it has sufficient capacity.

If you want to export the images from iPhoto to the Finder, then you won't even have to reformat it.

If you want to store the iPhoto Library then you'll need to reformat it to formatted Mac OS Extended (Journaled), which you do with Disk Utility.

It doesn't have to be a flash drive of course, any external HD will do too, with the same caveats.