Here is the source for the photo galleries used in my blog. Original source can be found at www.kirupa.com This actionscript and anything here is free to use < EXAMPLE HERE >
This method is cool because I can edit 1 flash file to change the look of all my photo galleries throughout the site, it is also cool because I dont have to touch the flash file when I add new photo galleries, I simply add 1 new xml file in a new numbered folder. The flash file is able to find this file by passing a variable at the end of embed and of object location (photo_gallery.swf?galleryLoc=%2Fphotos%2F#%2F1%2Exml) dots slashes and underscores have to be converted to hex
You may edit the flash file included (Flash MX and above) to change flash and standard images sizes or to change the look of it.
You have to edit the xml file to include the # of images, location, and captions.
The standard image size for these galleries is 446x335 pixels, so making a photoshop droplet that automatically resizes all your images to fit perfectly is the way to go, plus you can command it to save to files in sequence.. 1,2,3,4.jpg etc (droplet not required but is helpful)
To make this work with the files I provided, you will need to set your files up like below.

1.xml is used by the flash file to know how many and where the images are located . The xml file also has the ability to add descriptions or captions to each photo.(so when you add a new folder always include 1.xml so the flash file know where the images are)
Below is the HTML used to embed the flash.. the main thing you have to remember to include is the gallery_Loc variable (change the # sign in two places below to 1 if you want it to look in folder 1 for the xml file)