Any of the consumer real estate websites as well as those of the major companies in Brooklyn will give you plenty of open house choices.
I would suggest a different approach however. I would strongly urge you to work with an experienced agent. We know the market and will help you focus your search on the most appropriate properties for you. We can streamline your search, negotiate on your behalf, and take you through each stage of the purchase. I don't know if you currently live in Prospect Heights or are just looking there, but I can tell you that knowing the neighborhood as well as I do, many properties being called Prospect Heights are actually outside the boundaries.
Hope this helps.
Halstead Property, LLC
One other thing I forgot to mention. You can also filter your search by property type (ie: Single-Family Homes, Condos, Townhomes, etc.), price range, beds, baths and all more. Try it out. It's super easy. HAPPY HOUSE HUNTING!
You can easily search for open houses on Trulia for the area you are interested in. We have a search filter that allows you to specifically only see open houses for this upcoming weekend. Below is the link to open houses in your area:
Hope this helps!