Short answer:

StickyBrain can grab content from almost any application using one of three methods. These methods include: 

StickyBrain contextual menu

StickyBrain Services menu

Hot Keys

For more information on using each of these methods download the StickyBrain Reference Manual and see the chapter 'Shortcuts'. The only way to grab information from Firefox, Netscape, or other Mozilla bases browsers is to use hot keys. These browsers do not support the Apple contextual menu system nor the Services system. This is a deficiency in these browsers and not StickyBrain.

Long answer:

StickyBrain provides three ways of grabbing information for two reasons. First: convenience. Second: complete coverage. The first way to grab stuff into StickyBrain is via the Services menu items. All cocoa applications support Services, but most Carbon applications don't unless the developer has explicitly added support. If you try using a StickyBrain Service and it doesn't work you can resort to the second method of grabbing information. The second way of grabbing is via the contextual menu system. We have our contextual menu system working under both Carbon and Cocoa applications. Unfortunately, some Carbon applications like Firefox and Netscape don't support the Apple contextual menu system at all. Instead, they decide to invent their own contextual menu system which isn't compatible with Apple's. So how do you grab information in applications like Netscape where Services and contextual menus don't work? Easy, use our third method of grabbing: hot keys. Our hot key system will let you grab information from any application that support the Command-C Copy command. Select the content in Firefox and press a grab hot key that you have assigned. Presto, your selected content will appear in StickyBrain. The bottom line is that Apple's Services and Contextual Menu systems have different heritages and therefore different levels of support from the various applications out there. The good news is that StickyBrain provides a way to grab information from almost anywhere, but you might have to experiment with each of the three different approaches.