[Lizard]

OmniFocus is specifically for keeping track of things you need to do -- project deadlines, household chores, and everything in between.

OmniOutliner is for outlines -- text in lists, outlining and drafting essays or books, especially things like textbooks that have lots of headings and sub-headings.

OmniGraffle is for pictures, diagrams and flow charts -- a floor plan for rearranging your living room, a flow chart for how calls are routed in a tech support department, and other visual things.

If that's not the info you're looking for, perhaps you could explain what sort of work you're trying to do and we can tell you which Omni products might help.