Do I need to know Spanish to find a job in Buenos Aires?

Yes, those who know Spanish will find fare considerably better in the Argintinean economic climate. Actually, it's not just a questioning of knowing Spanish. You're either pretty fluent or you're not at all - these are the two classes of langauge acquisition when it comes to job opps. If you say you speak Spanish, you're not going to get by with a basic knowledge of colours and numbers.

That said, there are a number of jobs that cater specifically for English speakers. For the corporate types, these are predominately with multinational organisations - opps increasing in the banking and oil and gas industries lately. Otherwise, you can teach English (most positions require TEFL certification) or join the masses who have already made a niche for themselves in the world of all things online.

Check out Craigslist Buenos Aires for jobs catering particularly for foreigners.

Totally dependant on what job you're looking for. If you want to teach English it wont make much of a difference, but if you want any other kind of job, you will struggle without spanish. There are a number of good schools in BA, so i would recommend doing an intensive spanish course. Expanish www.expanish.com Expanish Spanish School are known for being one of the best schools in town (most professional anyway), or if you want something smaller, go for Vamos www.vamosspanish.com