Laptop Bags

Having recently obtained a new 15.4" laptop, I am now in the market for a messenger-style laptop bag. I have traversed the links of Google and Froogle, and have come upon many purportedly serviceable bags. The difficulty is that none of the listings mention where one is supposed to store the cord, transformer, and mouse. Every one of the bags seems to have a snug compartment for the laptop, and places to put papers, airline tickets, and the like, but I can't really see forcing the mouse into a compartment made for, say, a cell phone. My old laptop bag, which will, alas, not fit the new addition, had a 2.5" high/wide zippered pouch next to the cutout for the laptop where the accessories could fit nicely. Does anyone know of bags which take the need for power cords and the like into account?