I have a couple of domains, you probably have to. With the advent of cheap domain services, coupled with cheap hosting, it is really easy for anyone to host a website. As a result your domains, logins and a whole load of other passwords start to build up. As a result you get inundated with login and other information. You could store this on paper or in an spreadsheet. These are less than ideal, since they are insecure and not very pleasing to use. What you need is a simple to use program to store all of this information.
Domain Brain is a simple, and cheap, application that is designed to store information relating to your domains. It offers a very well designed interface. It makes adding your information easy to use. The idea behind this application is to fill out the forms with all of your login information. For example your FTP information, database, content management, hosting and registrar. They are simple to use forms which means you can fill out all of the fields within a couple of minutes.
This application does cost $15. Depending on how you use it is either expensive or really cheap. If you have 100 domains this type of application is really useful. It provides AES encryption as well as password support. As a result it is a lot more secure than your typical spreadsheet.
There are a couple of improvements I would like to see implemented. For example a method to add your own options to the main page. The default ones are good but every so often you will probably want to add your own information, currently there is no option to do this. Other than that the sidebar method of storing your domain information works well.
Defiantly an application worth thinking about. There is a demo available, so you can test it out. Another application that I would suggest is RAGE Domainer and if you want some cheap hosting check out WebHostingSearch, I have used them many times to find good hosting for myself and friends. It works along the similar lines, although is designed more for managing the domains statistics rather than login details.