I have taken to using thumbscrews for anything I can now. This makes it so much easier when you go back to do something and don't have to grab your screwdriver. Last year I did a massive install of a thousand plus dell units at a university it was so nice that you could deconstruct the whole unit and replace hard drives and other components without the need for a screw driver at all.

that sounds like the job from hell!

I always have a roll of haevy duty tape handy as well, to keep cables etc out of the way whenever I'm, prodding the inside of my computer

My tool box:

One laptop loaded with software tools, most portable and installed on my USB flash drive as well, and sorted by function using Pstart as menu.

Software on lappy only: VMmake, VMplayer, various HD diagnostic software.

Software on both lappy and USB key: Clam antivirus, Antivir, Avast, EasyDVDburner, smallcdwriter, 7zip, winrar,faststone image viewer, emailpassview, Firefox,FlashGet,GaimPortable,MirandaPortable,MSN Messenger,NetStatLive,Outlooker,PuTTY,RASConfig,RegEditPE,SuperScan,TCPView,ThunderbirdPortable,TraceRoute,Trillian,ViewTCP,VNCViewer,WS_FTP_LE,AudacityPortable,AudioGrabber,DVD Decrypter,DVD Shrink,Media Player Classic,MP3 Splitter & Joiner,VLC,Atlantis,PDFreader,SPREAD32,SunbirdPortable,SAMInSide,PassWordRenew,Passware_Kit_7.9.2141,FSCapture47,A43,ActiveUndelete,Aida32,Autoruns,jellybean'CIAUnErase,CPU-Z,DeadPixelBuddy,DefragNT,DependencyWalker,DirectorySnoop,DiskCheck,DiskInvestigator,DiskState,DiskTective,DLL Viewer,DriveSnapShot,DuplicateFF,EasyRecovery,Editor2,EffectivefileSearch,EnCase,Eraser,Everest,Explore2fs,ExplorerFAT,ExplorerNTFS,ExplorerXP,EZPCFix,FileRecovery,FileSearchUtility,FileShredder,FreeU ndelete,GetDataBackFAT,GetDataBackNTFS,HDM6-CD,HDSpeed,Itty Bitty Process Manager,MemTest,NortonDiskDoctor2005,NortonWindoctor2005,OnScreenKeyboard,PassMark,PEResourceExplorer,PowerQuest,ProcessExplorer,PTTD,RAIDReconstructor,RecoverMyFiles,Regmon,ResourceHacker,Restoration ,RightMarkMA,,SectorSpyXP,Services,ServIwin,ShellExView,Startup Control Panel,StorageInfo4Win,SymantecGhost,TotalCmd,TreeSize,UltraCompare,UltraEdit,UltraISO,UnknownDevices,UnstoppableCopier,WDDiagnostic,Windows Update files,WinHex,WinIE,WinImage,WinISO,XnView,Xplorer2,XWays,X-Ways,7 in one IE installer, process explorer.

USB flashdrive only: dual boot DSL and xp-PE

Regular IDE/laptop/SATA USB convertor for hooking up drive to my lappy so I don't have to boot their machine before scanning.

In pocket: Thumbscrews, One pocket screwdriver with replaceable heads, one USB wireless adaptor.

In my car: cat5e cabling, crimper/cutter tool, 80mm/120mm fans, one multiOS installation CD custom made unattended after selection (I use jellybean to change the key and activate afterwards) (allows use of recovery console for XP, 2000, 2003).

Handles just about anything I come across. All software fits on a 512mb USB flash drive with about 40mb free for play room.