I wonder how standard the business casual thing has become. When I went through interviewing just over a year ago at several tech companies, suits were standard, and I believe that's still the case at 98% of companies. Hopefully business casual will eventually become the norm. Of course you have to still present yourself properly, but the way you dress significantly impacts the first impression you make.

I can see how Google interviews would be fine to be business casual – it's a different culture.

Here in Germany it's perfectly fine at least if you apply as a programmer. In fact, when you arrive with a suit tech people often start to get suspicious. I know of one guy who wanted to test his future boss, so he arrived to the interview with ripped jeans. Turns out the boss did indeed ignore superficial things and was just interested in the software the guy created. He ended up working for them for many years...

I can confirm that in Belgium it's about the same thing as Philipp tells. Maybe that more international oriented companies like EDS, E&Y, etc. are different (in Belgium too I mean).

I should mention, the environment I was in was all college graduates. Though I think in general it still holds true for most US tech companies.