I use this website to find taxis. I discovered it last year when I was traveling to St. Petersburg and needed to get from the airport to the hotel. It came in handy then. I still check it periodically when needed.
I'm pleased that it gathers many taxi services and it's quite easy to navigate the site. You can read reviews and find additional information about the companies. Overall, it has everything you need, including rates. The prices listed, if they differ from the actual ones, do so only slightly.
