This comes highly recomended. It is like Microsoft OneNote, but tweaked for RPGs and a lot more robust.
The Keep is the perfect tool for Game Masters and Players alike! Quickly access and organize your campaign information - scenarios, creatures, maps, treasure, and more. Players can use it to keep track of all their characters, notes, henchmen, magic items, spells, and strongholds. Have more than one campaign? Not a problem! Use The Keep to organize any number of campaigns.
Organize your campaign information into intuitive folders
Track notes, maps, images, character sheets, handouts, and PDFs
Integrated word processor with spell checker
Fractal Mapper integration
Built-in Dice Roller
Inspiration Pad Pro integration for random names and encounters
Print a single document from your notes, maps, images, and character sheets
Can be run from a USB Flash Drive, or other portable drive
My friend's Favorites
It's really easy to move notes around and arrange them in various hierarchies. You don't need to plan out stuff in advance, just jot down various notes and later organize them.
* Fast, full-text search.
* date-stamped game logs
* I can link in game PDFs into the hierarchy, so various rulebooks etc are available without needing to tab out to a separate reader.
* It integrates with the other NBOS tools automatically, so I can add my Fractal Mapper maps into game notes with minimum fuss.
There are lots of nifty features, like I said. Sure, I have some things on my own wishlist for future improvements -- a more customizable dice roller would be nice (so I could use it in Exalted, for instance). But honestly... I've been very pleasantly surprised at how useful and stable this thing has been in practice.
There's one feature that sounds cool but which I haven't tried out yet -- but will once I get a separate monitor. The program has a "GM screen" function, in which you can display an image (or whatever) on a second monitor, with mouse pointer. So you could show player-suitable maps to your players, for example, or pictures of NPCs, while still keeping your GM notes visible to you on your main screen. Sounds like it would be useful at times.
There's a 30-day full-feature trial version available from the NBOS website, so... try it out and see how you like it. It works great for me, but everyone has their own preferences