If you've ever had to look for an apartment, you know that the entire process can be described in one word: tedious. However, you can streamline some of what you need to do via sites that specialize in apartment searches:

PadMapper is a map mashup that brings in results from Craigslist, Apartments.com, and Oodle.com.

HotPads is another map-based apartment search tool; you can narrow your search by location, monthly rent, bedrooms, etc.

Naked Apartments is NYC-based and offers apartment searchers the ability to find no fee rentals and do reverse apartment searches (brokers and landlords actually sending YOU listings to look at!).

No apartment search list would be complete without Craigslist, where you can find apartment rentals, post an ad for a roommate, and browse all kinds of real estate listings.
Do you have a favorite way to search for apartments online? A tip you'd like to share with the About.com community? Please leave your experience in the comments.
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Craigslist – This one of the best among all. This made me to find my current roomate and eventually he became as my best friend. Reason for saying that is the website got good people posting adds.
I love Padmapper as well.. it’s to bad what happened with Craigslist this summer. I found that using a supplemental Craigslist alert service is also a great way to get first dibs on brand new listings