Just got turned on to SeatExpert.com, which competes with SeatGuru.com, a service I use all the time. Both are exceptionally helpful for choosing seats on airplanes. Always keep one or both open when you choose seats on your booked flights.
Not long ago I had to change flight plans while in the United Red Carpet Club at SFO. The person behind the counter was helpful, but couldn’t answer questions such as “Which window seats are missing windows on this 757?”. So I pulled out my laptop, brought up SeatGuru.com, checked out the United 757-200 page and found out that windows are missing on rows 11 and 12. When I showed the site to the person behind the counter, she was amazed, and gratified that people other than United (with huge help from customers, actually) were filling in the airline’s blanks. Now I see that SeatExpert covers the same bases. With more detail in some cases. The competition should make both better.