There are IMAX theatres in most major metropolitan markets. I have been to several around the country. However, they are not usually freestanding theatres like a normal screen theatre. They are usually inside of or attached to another attraction such as a zoo or museum. If you ask, you can usually go to just the movie itself without paying addmission to the other attraction. Movie only admission runs $6-9 for an adult. Larger IMAX theatres have multiple movies per day. Movie A at 10Am 2Pm and 6Pm and movie B at noon, 3PM, 9Pm, etc. The image is so realistic, people are warned about getting motion sick. Just close your eyes for 10 seconds and you will recover and be able to resume watching.
Another great type of theatre is the one where there is an image projected 360 degrees around a large round room. The audience stands and mills around in the center. As you turn around, it appears like real life so you can see what is behind you, beside you or in front. This system is actually a set of 8-20 individual projectors where the screen edges line up perfectly. Look above the center of the room and you can see all the light beams.