I don't know if you were making a direct reference to Salesforce.com's "Employees have fun in the office, participating in foundation/volunteer activities with their peers and wearing Hawaiian shirts on Aloha Fridays." (http://www.salesforce.com/company/careers/culture/)

I consider the whole Hawaiian shirt thing to be a "gateway" perk. If the company promotes wearing fun attire, then you can be sure to expect other more exciting perks. I don't know of any Silicon Valley software companies that advertise Hawaiian shirts as their one and only perk...

I also think Salesforce.com's volunteering perk is very enjoyable and worthwhile. You essentially get paid to do a workday of community service each month. Didn't sound very exciting or interesting at first, but it turned out to be extremely rewarding. I'd love to see more software companies adopting similar programs and following suit.

Wear a different shirt day doesn't cost anything and isn't a perk in the sense we are discussing here. It's a conscious attempt at influencing company culture. Nothing wrong with it (unless its a Hawaiian shirt) but it isn't a perk.

I think it was an Office Space reference.

It was. I didn't know anywhere actually did it :/