Memo Plus  
   Replacement for the built in Memo Pad. Add drawings, start from a template, even set an alarm for a Memo. Site includes library of users' templates. From Hands High Software. Shareware.
   http://www.handshigh.com/html/memoplus.html

pedit  
   Memopad replacement that breaks the infamous 4k barrier and adds all the functionality of a true power text editor. Imports and exports Palm DOC format. [Shareware]
   http://home.columbus.rr.com/nevai/palm/

WordSmith  
   Full-featured word processor, doc viewer and enhanced memo pad available for the Palm organizer. [Formerly known as BackupBuddy Software, LLC]
   http://www.bluenomad.com/ws/prod_wordsmith_details.html

Documents To Go  
   Use Word, Excel, and PowerPoint files on any Palm, Visor or Clie handheld. Chosen by Palm to be included in the m500 series. Add-in allows email sync and PDF file viewing. Commercial. Starts at $49.95.
   http://www.dataviz.com/products/documentstogo/index.html

SiEd - Text Editing for Palms  
   User guide and download for a Memopad replacement with the ability to edit large text documents. The source code is available under the GPL.
   http://benroe.com/sied/