It is probably a good idea to keep the original value and the currency rather than converting them to dollars just the one time. This will allow you to recompute dollar figures based on currency exchange fluctuations.

I'm not convinced it's useful to convert the currencies anyway. I can't get paid in US dollars for this job. If I wanted to get paid in USD, I'd be getting a different job.

Or are there any cases where a single job market spans two or more currencies?

Some larger companies have offices in more than one country. Examples would be Google, Microsoft, Facebook, most banks, etc.

Perhaps it would be useful to be able to view the results in any currency you desired. But already we're entering scope-creep territory :-)

Right - if you cared enough about looking at anonymous salary information across different countries, you could just use Glassdoor.com.

The point of this app is that you share a link with your peers, whether they're based in your office or in an office in a different country. This is a bit different from completely anonymised data from statistically similar market segments (and possibly more useful, since people at the same company are likely to have similar perks and benefits etc.)

There are at least 4 different currencies being used to pay people in my office. Sometimes two different currencies to the same person. As each portion is (or can be) negotiated separately, this isn't merely a conversion question.

Also, our bonuses are denominated in USD and then converted (or not) into whichever currency we prefer.