This should work to query multiple post types:

query_posts('post_type[]=post&post_type[]=page&post_type[]=event');

You can even test it directly into your browser, www.yoursite.com/?post_type[]=post&post_type[]=page

This should work to query multiple post types:

query_posts('post_type[]=post&post_type[]=page&post_type[]=event');

You can even test it directly into your browser,

example.com/?post_type[]=post&post_type[]=page