Rather it should be et aliÃ¦ , or et alii depending on whether the subjects are female or male respectively. Roughly means "the rest." Apparently you can use et alli or the abbreviation: et al. for groups with both men and women making the whole gender issue a moot one. I've seen this used before, and frankly never thought much of it.
Recently though, I got an e-mail from somebody and it just reeked of douchebag, especially when he said this ((I'm paraphrasing so I don't offend anyone, but it is exactly the use of et alia that I am discussing here)):
After that, Joe and I (et alia) will be planning the destination stops...
I had to find out for sure what et alia meant, and this lead me to the list of Latin Phrases page in Wikipedia, see et alia is so small that it doesn't even get a wikipedia page; nobody has deemed this teeny phrase important enough to describe it at length; unlike et cetera. If you insist on knowing more about it as I did, you'll find that its use is also a little vague, let me guess why? Because its a fucking dead language phrase that nobody uses. Indication number two that you should not be using it is when you're only talking about you and one other person --I know there isn't anyone else involved in this case.
If you're going to say "et alia" then you are using the full phrase and its not abbreviated! If you are going to use et al then note that "al" is abvreviated and so it should be written like this et al., no parenthesis.
Don't use this in informal or casual e-mails, save it for your thesis or your final grade essay where you should sound smarter than you really are. It can almost always be substituted with the words "and others" you can read a little more about it here.