Tools like iPhoto and Picasa have their place but they are somewhat bloated, and can slow down your viewing experience.
CocoaSlideShow is a simple, free and fast program for viewing your photos on Mac. Simply fire it up, enter a time interval you want between each slide and sit back to enjoy your photos. You can watch slideshows in full screen and also edit EXIF and IPTC metadata. The only other options are the ability to rotate and delete photos.
There's little to CocoaSlideShow beyond that however, and those looking for online album uploading, Facebook integration and photo editing options need look elsewhere. It does support geo-tagging though, so that you can geographically link to your photos (assuming the device you took them on supports this). You can also use your Apple Remote to navigate through slideshows.
I really liked the simplicity of CocoaSlideShow. It's refreshing to use a straightforward, elegant photo viewer that does exactly what it's supposed to with no fuss. The only problem I found was that exiting full screen slideshows sometimes ended-up with a black screen for a while before it finally reverted back to the desktop.
If you don't need anything fancy to view your photos in, then you can't do much better than CocoaSlideShow.
