I know a couple people who use Memopad all day long on their BlackBerry but are looking for more features. ActionPad may be a possible solution and is currently in public beta from S4BB. The software attempts to give you quick access to memos with (multiple) categories, encryption, and more. They also support exporting via Email and multiple font sizes. They claim it works together with Memopad but I have not had a chance to put it through its paces yet.
You can sign up for the beta at this link but you may want to do it from another email address since they tend to send you spam and there is no option to opt out until after they send you something.