I too agree about power2ool - I don't use it for monsters (as I can't print them as my browser is too old for the print function) but for selecting magic items. Its great for that - being able to browse through various categories of magic items of a given level, then drag them into a screen where you can look at multiple items at once is very helpful in deciding what each of my players might like best for their character.
Which is really important to me as I have one player that only wants items that are characterful for his PC, and another who only wants items that are mechanically advantageous to his PC (and has a much narrower conception of what items are "good" than I do). I also have a PC who has a really hard time remembering triggered actions and 2 players that play by webcam and therefore have a hard time using items that require a firm grasp on who is located where on the battle map... power2ool, by letting me look simultaneous at multiple specific items, really helps me chose the best items for each PC.
And the fact that you can have multiple such windows means that I can plan the items for several levels at a time, which saves me a lot of work.
So, yeah, awesome program.