are using VARCHAR fields: thesevariable-length columns are particularly prone to fragmentation. Quicker emailsDifficulty: Easy Application: KMail Can't afford to waste three seconds locating your email client?Can't be bothered finding the mouse under all those gently rottingmountains of clutter on your desk? Whatever you are doing in KDE, youare only a few keypresses away from sending a mail. Press Alt+F2 tobring up the 'Run command' dialog. Press return and KMail will automatically fire up, ready for yourwords of wisdom. You don't even need to fill in the entire emailaddress. This also works for Internet addresses: try typingwww.slashdot.org to launch Konqueror. Paralleliseyour buildDifficulty: Easy Application: GCC If you're running a multiprocessor system (SMP) with a moderateamount of RAM, you can usually see significant benefits by performinga parallel make when building code. Compared to doing serial buildswhen running make (as is the default), a parallel build is a vastimprovement. To tell make to allow more than one child at a timewhile building, use the -j switch: make -j4; make -j4 modulesSave battery powerDifficulty: Intermediate Application: hdparm You are probably familiar with using hdparm for tuning a harddrive, but it can also save battery life on your laptop, or make lifequieter for you by spinning down drives. hdparm -y /dev/hdbhdparm -Y /dev/hdbhdparm -S 36 /dev/hdbIn order, these commands will: cause the drive to switch to Standbymode, switch to Sleep mode, and finally set the Automatic spindowntimeout. This last includes a numeric variable, whose units areblocks of 5 seconds (for example, a value of 12 would equal oneminute). Incidentally, this habit of specifying spindown time in blocks of5 seconds should really be a contender for a specialuser-friendliness award - there's probably some historical reason forit, but we're stumped. Write in and tell us if you happen to knowwhere it came from! Wirelessspeed managementDifficulty: Intermediate Application: iwconfig The speed at which a piece of radio transmission/receiverequipment can communicate with another depends on how much signal isavailable. In order to maintain communications as the availablesignal fades, the radios need to transmit data at a slower rate.Normally, the radios attempt to work out the available signal ontheir own and automatically select the fastest possible speed. Infringe areas with a barely adequate signal, packets may be needlesslylost while the radios continually renegotiate the link speed. If youcan't add more antenna gain, or reposition your equipment to achievea better enough signal, consider forcing your card to sync at a lowerrate. This will mean fewer retries, and can be substantially fasterthan using a continually flip-flopping link. Each driver has its ownmethod for setting the link speed. In Linux, set the link speed withiwconfig: iwconfig eth0 rate 2MThis forces the radio to always sync at 2Mbps, even if other speedsare available. You can also set a particular speed as a ceiling, andallow the card to automatically scale to any slower speed, but go nofaster. For example, you might use this on the example link above: iwconfig eth0 rate 5.5M autoUsing the auto directive this way tells the driver to allow speeds upto 5.5Mbps, and to run slower if necessary, but will never try tosync