Is there a way to use boolean operators in a gmail search filter? As in, From e-mail OR e-mail?

Or do I just need to make a new filter instead? Thanks!

Yes, you can use boolean operators in gmail filters.

For example, you can create a filter that looks like this in the From field:

(someone@somewhere.com | someoneelse@here.com)

The "|" is the OR symbol, so the above would match either someone@somewhere.com or someoneelse@here.com.
You can also just use "OR" if you prefer.

Here’s the Gmail help page that talks about how to do it:

https://mail.google.com/support/bin/answer.py?answer=8870