I'm currently looking into ways to create InstaCalc widgets/gadgets/plugins (you know what I mean) for your website. There's a bunch of platforms out there:

• Google Gadgets
• Windows Live Gadgets
• Embed object tags like YouTube. I previously made a simple version to do this, and want to see if there's a better platform.
• Plain ol' static HTML to stick onto your site: fast and simple.

I'm a newcomer to this space and will be researching the various options - I'd love to hear any experiences (good or bad) that people have had in this area.

Sure, the easy answer is to "build 'em all!" but time and energy are usually finite resources.

UPDATE (10/30): Embeddable InstaCalc is alive! Click the "embed" link on any page for the code you need and a live preview. Here's an example BMI calculation.

I've chosen option E), none of the above. I decided to build a system in the style of adwords: a bit of JavaScript that you insert into your site, something like this (script tags intentionally broken):

<scrip t>
instacalc_embed_url = 'http://instacalc.com/?d=blah...';
instacalc_embed_height = 300;
</scrip t>
<scrip t src="http://instacalc.com/javascripts/embed.js"></scrip t>

Here's why I went with this approach:

• Entirely updateable on the backend. If there are any bugs in the layout, I can fix it on my end.
• Including script tags should be familiar to any Adwords user. Also, the code is smaller since there aren't table tags, etc.
• If InstaCalc is down, the script will not be loaded and nothing will be added to the page. This feature was key - including an IFrame or Object directly could have bad consequences if the site was not available (such as an ugly 404 message in the middle of the page!). Now that is not an issue - any ugliness comes from my layout, or your formulas .

Embeddable formulas are officially open for business - any feedback on your experience is welcome.