The web was originally stateless and we've done everything we can to change that over the years.  Hidden viewstates, sessions, cookies, and XMLHttp are all ways to help make web applications ... well ... less like web applications.  This isn't good or bad, it's just what's happening.

However, the rise of Firefox as the preferred browser among the tech-savvy says something ... people LOVE tabbed browsing.  It's quite possible that if Microsoft doesn't release a version of IE without tabbed browsing, IE's dominance could be in some trouble.  Firefox is slower, more bloated, and less stable than IE, but people love it and many would take a kick to the jimmies before switching back.

With this in mind, the less state that certain types of pages have, the more useful they become.  When you can encode data that a page needs in the querystring you make it more useful to tabbed browsers, as users can pass this information to a page easily.  After making this realization, when I've been making web-based tools for myself and others that I know use Firefox, I put everything in the querystring, like most of us used to do a few years ago before ASP.NET.  The backend for one of my messageboard sites has lists of posts with "delete this" links with URLs like:

MacDaddy.com/backend/forum_admin.aspx?mode=delete&post_id=123456

and pass no other information (although session information is passed via a cookie).  Until I started using Firefox more, I had bought into ASP.NET's new practices wherein data got stuffed into viewstates and I checked IsPostBack right from the start.  But these days, that probably won't be happening so much.  My sites are moving in one of two directions, neither of which leverages some of ASP.NET's features.

One direction is what I just talked about, making sites less stateful.  The other thing I've been doing lately is keeping state information in XML and using SOAP/XSL to handle a lot of the interaction between the page and the web server.  I'll blog more about this way later and I'll try to include code.

So, as always, our industry marches on and we have to also.  I know that many people are excited about ASP.NET 2.0 and SQL Server 2005, but I have a feeling that Firefox might have a bigger impact on web development than anything Microsoft releases this year (assuming that developers learn how to leverage some of the features of Firefox).  I'll qualify that by saying that all my information about ASP.NET 2.0 and SQL Server 2005 comes from bloggers and that I'm likely to adopt both as quickly as possible, but I still think that Firefox is a big deal.