Last week while I was on my friends iPad I pulled up a web site that I had created and it got me thinking about the role that Flash will continue to play in the world of web development, but also about how it should be used responsibly. As you know Apple don't like Flash, so it won't show up when your web sites are viewed using their products. As the number of ppl using Apple continues to grow, the importance of creating a non-Flash friendly web site will become more and more important in the web development world.
I recently re-designed a web site for a building contractor whose initial hire had built his site ENTIRELY out of flash. This is a bad idea not only because some computers don't have flash (even some PCs don't have flash installed), but also because an all-Flash web site loads slowly and is complicated to use. This client was MORTIFIED when he saw what his initial hire had put together, as even he couldn't figure out how to navigate the site!
One option for creating a non-Flash friendly site is to embed a code into your index page that loads a different, non-Flash version, of your site when it senses that the browser doesn't have Flash installed/enabled; but this means creating your web site twice, a lot of work. I employ a different strategy. Embed your Flash elements into your page in such a way that they compliment your site, but are not essential to the function or design of your site.
What this means, for me, is that the Flash animation should not take up more than one quarter of the first screen people see when they visit your site. Important: I didn't say one quarter of the page, it's one quarter of the screen. Given the many different screen resolutions that exist, there is no way to pinpoint the exact dimensions of 1/4 of the screen, but you can get pretty close by making your decisions based on the most commonly used screen resolutions (today most users are using a screen resolution of 1024x768 pixels or higher, with a color depth of at least 65K). You can see more at this link:
http://www.w3schools.com/browsers/browsers_display.asp
The reason you don't want the animation taking up more than 1/4 of the screen is, that way if the animation doesn't show up, it won't be missed too much. Most designs are not "broken" by a 1/4 page of free space (in fact it actually compliments many designs by letting the page "breath" a little).
Another rule for Flash is that, obviously, the background needs to be transparent. That way if the user's computer doesn't have Flash, they'll just see a little more of the background, instead of a white box that says "plugin missing".... UGLY! (CC Flash Firestarter will allow you to create animations with transparent backgrounds.)
And obviously you don't want ANY part of the function of your site to rely on Flash, otherwise you are basically telling all of your Apple users that the information you're providing isn't for them. And of course there is also the small percentage of PC users who don't have Flash installed either because they are technologically illiterate and don't know how to install it, or they simply don't want it for reasons related to computer speed, etc.
Take my own company's web site, http://www.sprucepinedesign.com, for example. You notice that the Flash animation takes up a nominal amount of space in an area of the web site that doesn't rely on content to look nice. If you dis-able Flash in your browser and pull the site up again, you just see the nice blue sky background instead of the animation, and you'll not even know that something was ever supposed to be there.

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