If you're like me, speed is one of the main areas I always like improve in. Whether its finding new little macros or simply standard AutoCAD or Express tools to quickly do repetitive tasks. Well an AutoCAD 2006 Express tool I frequently use is SAVEALL. This nice little code will Automatically do a QSAVE on all the currently open drawings you have open. Whats nice is some people (Like me) usually leave that pesky drawing1 open. Well the SAVEALL will cycle through all your drawings, once it hits drawing1 it will prompt you for a save as. You can save, or just hit cancel and the routine will continue to run and save the rest of the drawings. Its a very speedy command. Along with being very handy when working with many XREF's, where you can make sure your base drawing and all the extra XREFS you have open are saved, then can be reloaded into your base drawing.
If you need to close all your drawings there is a command for that also. CLOSEALL will simply close all your currently open drawings back to the blank AutoCAD state. This command I don't usually use but some may find it to their liking.
The one I commonly use (Typically when getting ready to go home) is the QQUIT command. This command will attempt to close all open drawings, offering to save any modified drawings, then exit AutoCAD. If a drawing has not been named yet, QQUIT will prompt for a file name. Then will shut AutoCAD down for you.
All these commands can be found in the AutoCAD 2006 Express tools pull down under Express>>File Tools then your desired command.