I just discovered this blog http://www.racialicious.com/ and want to share its post on Cinco De Mayo:

A FRIENDLY REMINDER ABOUT CINCO DE MAYO
By Special Correspondent Arturo R. García; 5/5/2009
http://www.racialicious.com/2009/05/05/a-friendly-reminder-about-cinco-de-mayo/#more-2420

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Here's an excerpt from that particular blog post (I found the entire article as well as the readers' comments to that post to be interesting reading).

1. This is not Mexican Independence Day
Nope, that's September 16th. 5/5 commemorates an unlikely Mexican victory over the French at the Battle of Puebla in 1862. The battle delayed, but did not stop, an eventual French occupation of the country, which lasted three years before it was toppled.

2. This is not that big of a deal back home
Don't let the beer ads fool you; 5/5 is a regional holiday, usually celebrated at the site of the battle. But, it's nowhere near as big a deal as it is in El Otro Lado. Now, is that because of immigrant pride, or American corporate opportunism? That, I leave for you to decide. During my time working in local Spanish-language radio, the biggest sponsors for our Cinco de Mayo concerts were — you guessed it — beer companies. Banners everywhere, beer girls hawking their wares on the stage, booze selling like hot cakes in the fenced-off drinking area. I don't doubt that at least some of the people who attended the events had their hearts in the right place, but the commercial aspect definitely got on my nerves when I thought about it.

3. 'Celebration' does not equal acceptance
Sure, people around the country will don their fakest sombreros and sing Ricky Martin at karaoke bars — because all Latinos are from Mexico, right? — but the furor over the H1N1 virus revealed examples of how we're still Others here, no matter the method of emigration..