For those of you who aren't aware of it, Mac OS X has a fantastic, and somewhat hidden away, feature to easily view images as a slideshow or an index sheet.
The feature is simply referred to as Slideshow and there are number of ways to trigger it. The most apparent option is to open up a number of images in Preview and then choose Slideshow from the View menu (Cmd + Shift + F).
Another way to start a slideshow is to select the desirable number of images in Finder and then right-click on any of them and then choose Slideshow from the context menu. What is thorougly annoying, though, is that you can't do this on a folder, but only images. Therefore, to view an entire folder with images as a Slideshowyou need to first select all files (Cmd + A) and then right-click on them to be able to start the Slideshow from the context menu.
Within the Slideshow view, when you move your mouse around, you are presented with a small toolbar giving you a few basic options:
Back (Arrow left)
Stop (actually, Pause)/Play (Space bar)
Next (Arrow right)
Index Sheet (I)
Fit to Screen/Actual Size (F/A)
Add to iPhoto
The, by far, coolest and useful feature is the Index Sheet. Just open a Slideshow and press I to zoom all the opened images out into an Index Sheet. It will automatically adapt the size of each image so they are all viewable without scrolling. Navigate around with arrow keys and press Enter to select an image and go back to the regular Slideshow view.
Then, of course, the most outstanding way to do this is through Quicksilver. First, make sure that Slideshow Action is enabled under Plug-ins:
When you've made sure that it is enabled, trigger Quicksilver through your preferred keys (in my case, Cmd + Space bar), navigate to the desired folder, press Tab and then S followed by L (or browse down in the list of options with the Arrow down key) to choose Slideshow. Press Enter and your Slideshow starts! Do all of this fast, and perhaps followed by the I key to show the Index Sheet, and both you and your friends will be mightily impressed, wondering what hit them. :-)
So, the short list version: press this key sequence to accomplish it all:
Cmd + Space bar (for Quicksilver)
B (e.g. for the Bora Bora folder)
Tab (to move focus to the action field)
S followed by L (to select Slideshow)
Enter (to start the Slideshow)
I (for the Index Sheet)
Note: All keyboard shortcuts mentioned are case-insensitive (or rather, lower-case if there's any problem).