I just deployed the latest version of Daily which uses canvas-based implementation of Identicon. If you use a browser with Canvas element support (Firefox 1.5+, Safari 2.0+, Opera 9.0+), take a look at some of my posts with comments (including the one that started the avalanche if you want to see the rare sight of 400+ canvas elements being rendered on the fly). You'll notice that identicons look much smoother looking now. On IE, it looks the same. I could have used excanvas but I didn't feel it was stable enough.
One thing that puzzles me though is that Firefox 2.0 seems to fetch the URL of image element inside the canvas element when I was expecting that to happen only when canvas support is not available (i.e. no canvas support or when scripting is off). That hurts, particularly for monstrous posts with hundreds of identicons. Currently, I am detecting only problematic canvas support (Safari 2.0) to generate canvas tag without image element within it but it looks like I'll have to do more to emit only the canvas tag if I am going to avoid unnecessary image requests.
Anyway, let me know if you run into any problems seeing identicons. Meanwhile, I am going to spend some quality time with the Identitune idea.
Update:
Apparently, identicons are not rendered on javascript-disabled Firefox browsers because canvas support is not disabled when script is disabled. They should spell out expected behavior in the canvas spec. While at it, an attribute for specifying data is needed. For now, I am using title attribute but that feels wrong.
Update 2:
Fixed noscript/canvas issue by adding img version inside noscript tag. Fixed unnecessary img URL fetch in Firefox by skipping fallback img tag inside the canvas tag (this speeds up canvas version load lightening fast, even with 400+ identicons in a page!). I think canvas support in browsers needs to workout these common issues.