I am interested in using one of the above for the designs on my site, however i have heard that Flash can adversely affect your ranking on the search engines. Any tips?
Flash is getting better at being searchable by search engines, but is better avoided for websites. For one thing, some devices like iPhone and iPad don’t support flash.
As for JavaScript, it’s fine to use if your site doesn’t depend on it. That is, you site should be fully accessible without JavaScript turned on. If that’s not the case, both your visitors and your ranking will suffer.
If you use flash correctly (i.e have alternate content that gets displayed when flash isn’t available) you can quite happily use it in websites without being penalised by search engines. I’m sure many sites, e.g any of the world-class award winning sites at thefwa.com would disagree that flash “is better avoided for websites”.
They may not be so happy when their iPhone visitors say—“hey, your site is just a (nearly) blank page”.
That’s one thing to certainly keep in mind these days–the number of people surfing the internet these days on mobile devices which don’t support flash.
For the type of site that might justify relying heavily on flash (interactive/immersive marketing sites in areas such as fashion, film, premium brands) the user experience is typically heavy on animation and multimedia, and hence cpu and bandwidth unfriendly. These aren’t going to translate well to a mobile experience anyway, whether flash or html5. They’re aimed at a specific market and medium, and if the kind of agencies that do these as part of a campaign feel it’s essential to have presence within mobile market they’ll have an alternate site or app.