I think TBag is one of the very first addons I ever installed. It’s been part of my UI since March 2007 (about a month after I started playing WoW).
TBags is an indispensable inventory addon. It works right out of the box with no additional fiddling. It shows your inventory all-at-once and then sorts it into logical groupings.
That said, if the arrangement doesn’t please you, you can fiddle with it.
This addon allows you to view the inventory of this toon or another toon by choosing which toon from the dropdown(#1 on the picture). You can also remotely view the bank of the toon chosen(#2 on the picture).
At the bottom of the layout window is the search box (#3 on the picture). Typing words or fragments of words into this box will search your bags and bank of any toon listed in the dropdown. It will display what it’s found in the chat window.
See the picture to see how the default bag is arranged.
The only failing to my eye is that this doesn’t inventory/search guild vaults. Shefki, the addon author has mentioned he may add this in an upcoming patch.