37signals is a much hyped company in Chicago (read about their passionate user rating here) . But keep an eye on them if you're into product development and Internet.

For a background of the firm read the Salon.com article "The next web revolution".

However, it's not the company or even their products that caught my interest.
It's their philosophy, which includes;

less is more
design first (then code)
find people who are enthusiastic
don’t try to find “tricky” ways to get more cash. Earn it.

To find out more about the hilosophy, read their blog 'Signal vs Noise' or even better, download their book (no hardcopy) for 19 USD. Excellent and straightforward reading. Like their products.