I first had to create the photo collages which make it up. I did this by first figuring out what size the collages had to be to both fit within the page without having a horizontal scroll bar appear and to have the individual images fit well within them. I came up with a size of 677 pixels wide by 335 pixels tall.  This allowed me to include 12 images measuring 107 pixels wide by 160 pixels tall each and to have a 5 pixel wide space between each photo.  Here's the math:

Width: 6 x 107=642, 7 x 5=35, 642 + 35=677
Heigth: 2 x 160=320, 3 x 5=15, 320 + 15=335

Using Corel Photo Paint, which is a photo editing software similar to 
PhotoShop, I then created the backgrounds for the collages measuring 677 x 335 pixels each and I pasted the individual images onto them (leaving a 5 pixel space all around the perimeter and in between the images). In all, I put together 9 of these collages for the intro slideshow on this site.  4 of 12 small images each, 4 of 1 or more medium images (331 x 160) combined with small images and 1 of the large and final image (667 x 325).

Figuring out how to make up these individual photo collages was tricky enough, but the effect I wanted of having some of the individual images change while others do not, was even trickier.  Here is how I was able to accomplish this:

As I mentioned before, there are a total of 9 photo collages in our intro slideshow.  Everytime you see some of the individual images change, you are actually looking at a whole new collage of images.  However some of the individual images are repeated while others are not.  The ones that are repeated do not seem to change because they are being replaced by an identical image while the ones that are not duplicated are the ones you see changing.  I then alternated which are duplicated and which are not duplicated to give it the final effect.

 

I'm not sure if this makes any sense, so I have included the 9 photo collages I used in our flash intro below.  Hopefully seeing them will make this process easier to understand.  They are shown here in the same order they appear in the slideshow.  Be sure to note the pattern of which images are duplicated from one collage to the next and which are not.

(Scroll down to view the photo collages.)
 

As you can see, every other image is duplicated from one collage to another making it seem as if only the non-duplicated ones are changing.  This pattern is repeated as many times as necessary to get all the images in.

 

Finally, I replaced three of the images with one larger image until the whole collage was made up of 4 larger images and then I replaced those with one even larger image for the final image. 

I then created the actual slideshow with Flash Slideshow Maker, using the "Fade In" transition and the "Photo Only" theme. 

That's pretty much how I did it.  I know that it's complicated and time consuming to do all of this, but in my opinion it's worth it. The flash intro is the first thing people see when they visit your site and if done correctly, it can create quite an impression on them.  

If you know of an easier way to create a similar flash intro, such as with a specialized program, please let me know so that I can share it here.

The nine photo collages which make up our flash intro slideshow: