I remember when FLASH was the big thing. I was a freelancer and it was 1999.
I went to so many web sites. Almost all of them were a let down. Questionable content presented in frustrating ways.
People got caught up in FLASH. Everyone was a Flash developer.
At the time, FLASH (or at least 90% of the implementations I saw) did not make sense to me. I advertised myself as someone who made “subtle use of Flash”. To me that meant “practical” use of Flash.
AJAX is the big thing right now. AJAX is pretty cool. I really like that the BIG THING with AJAX is NOT the wow factor, it’s the improved usability – at least that’s the big thing in my books. That said, there will be lots of sites that get caught up in the WOW and lose sight of the usability.
We use AJAX on 2ndSite now and we will use it more. Our use is so “subtle” you may not even realize we use it. We use it to enhance performance (page loading).
Flash is 99% bad is a concept I heard about Friday. It stands for 99% bad implementations. I’m curious to see how people use AJAX and what the implementations turn out to be. There are a lot of browser compatibility issues with AJAX. The “Back” functionality is problematic.
I’m a glass is half full kind of guy. What do you think? Ajax is 62% good? I guess we’ll have to wait and see…
Michael McDerment 
“I think it's important to note a few things:- technologies themselves aren't "bad", it's the people who implement them that aren't doing the appropriate homework- Not all web projects are intended to be "highly usable". Though I personally feel that usability is very important, I think it's OK for other people to opt not to care about usability, for other reasons.That said, yes, I'd say Ajax is, maybe 70% good….and flash, well, 70% bad..wouldn't go so far as 99% because there are flash implementations out there that are well done.”
“I think AJAX, when used in moderation, is mostly good. Basically, I see it as a vehicle for improving the user interface for many common user interactions within the context of a larger application that is mostly "pure" thin-client (HTML).I get a little concerned about applications that are totally designed around AJAX. These kinds of applications start to manifest the same types of issues we had with other "rich interface in a browser" type solutions.”
“I agree that Flash is usually implemented in very, very wrong ways, and I guess it is used in a bad way most of the time.As for AJAX, I think it is great that most people are using it to enhance usability and performance. But "enhance" is the key word here. I don't think whole web services should be based on AJAX technology.”
Well put.I have a semi-rant about Ajax here – http://tim.blog.kosmo.com/blog/_archives/2006/1/18/1682146.html