Contract or permie? Quick app to compare contract rates to permanent salaries

I've always had a spreadsheet to help me compare a daily contract rate to a "standard" salary, to ensure I'm always comparing like for like when considering jobs. A newer wrinkle has been recruiters quoting "package" salaries, which just means you need to multiply by 0.91 to get the "standard" salary (ex super). But it's always been confusing.

I've recently been sharing my spreadsheet with friends who've been considering contract jobs. The spreadsheet was fine, but a bit clunky and I'd only ever bothered to make it convert daily rate to "standard" salary.

To make this work a bit better, I created ContractOrPermie.com, a little one-page application I wrote to allow you to quickly and easily compare contract rates with standard salaries. It's only really suitable for Australia.

As well as nicely solving this particular problem, I also got to try out Twitter Bootstrap, which means it looks great in all browsers without me having to futz around with CSS. I'm hosting it using the new functionality Amazon Web Services have launched to allow static file hosting at the root of a domain using Amazon S3 (in the new Australian data centre).
Anyway, check out ContractOrPermie.com and let me know what you think.