Hotel Property Management Systems (Software as a Services, SaaS)

I did a small research recently to discover any solutions for small hotels and the needs of those hoteliers.
Some findings so far:

http://www.clerkhotel.com/, probably the most shining UX

http://www.instamanager.com/

http://www.roomsy.com/

http://www.planyo.com/

http://www.keepmebooked.com/