The Ducati Monster List web site (http://www.ducatimonsterforum.org/) is full of interesting chatter about riding and modifying monsters. It has one unpleasant side effect though - if you spend even a few minutes on the site you tend to get excited about making changes to the bike. Things that you previously didn't even notice, now really really bug you. The #emissions_cannister for example

Spare parts catalog - http://www.ducati.com/bikes/catalogs.jhtml;MY=2002

rearset bolts: 4 M8x40-1.25 and 2 M10x25-1.5

Hacks

suspension

http://clubhousemotorsports.com/ - Eric Colbath in NH is an ace Ducati tech. He rebuilt my forks and they're vastly better than stock. After 10 years at BCM he's doing his own thing.

http://www.computrackboston.com/ - Peter Kates is a suspension guru in Bellingham, MA (down on the RI border).

reflectors

Everyone removes the reflectors from the front forks. I hadn't noticed until I read about it, and then sure enough they started to bug me. They're nasty little plastic things stuck on with double-sided tape. They're clearly tacked on at the last minute to meet some regulation or other. The good news is that they're easy to remove with a hair dryer and a little elbow grease. One almost fell off, the other needed a little convincing with a screwdriver. Afterwards the forks needed a little cleanup with some alcohol to get rid of the crusty glue that the adhesive tape had left behind.

gas tank stickers

Again, a little heat with a hair dryer and some careful peeling got the two gas tank stickers up. A better idea than the hair dryer is to just leave the bike in the sun for an hour or two - I'd bet this will heat the tank more than the hair dryer.

I stuck the stickers on the inside cover of my owner's manual just so I have them for reference.

emissions cannister

Purely cosmetic, but it's surprising how much better it looks when it's done.

http://pg.photos.yahoo.com/ph/jerseyjeffshinn/album?.dir=c233&.src=ph&store=&prodid=&.done=http%3a//pg.photos.yahoo.com/ph/jerseyjeffshinn/my_photos

exhaust

You can hack on the stock exhausts to make them louder: http://home.earthlink.net/~desmoduck/muffler_mod.html

Or you can pay someone to do it: http://www.ducatipipemod.com/. I went this route (got the "1/2 mod") and it's amazing how much of a difference it makes. It's a little louder (but not obnoxiously loud) but the sound is magnificent. Not as deep as a Termignioni or Arrow but great value for the money.

rear brake

http://www.tcmproducts.com/Ducati_Rotors.html will drill lots of holes in your rear brake rotor to make it lighter.
http://forums.13x.com/showthread.php?t=117260 - another shop that does the same thing.

Mirrors

http://www.constructorsrg.com/products.html - expensive but very high quality. I've got 'em, they work great and are beautifully made.

Turn Signals

http://www.custombike.org/shock_racing_marker_lights.htm - LED's, about $25. Some talk that they're not very durable.

http://www.cyclegear.com/spgm.cfm?L1=3&L2=&L3=&L4=&item=MRX_OI1_G - look like OEM, but smaller. Bulbs.

LED's

http://www.customdynamics.com/flex_led_array.htm

http://www.radiantz.com/cart/index1.html?1.html&1

Homebrew:

Horn

You can never be too loud.

http://www.ridesafer.com/page/mfc0/Home.html
http://adventurersworkshop.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=AWI&Category_Code=Stebel_Air_Horns

License Plate Lights

http://www.watsendesign.com/products/current/LEDPLATELIGHT/index.html
http://www.4strokesonly.com/LicensePlateLights.html

Light modulator

Blink your headlight and brake light for better visibility: http://www.kisantech.com/

Cool Paint

http://www.frostysfinishes.com/ - guy in NH that does some amazing stuff with paint.

Misc

http://ducatimonsterforum.org/index.php?topic=22908.0 - Monster under seat tray alternatives

Track Days

http://www.fishtailridingschool.com/ - well-run track days with classroom training and small-group instruction
http://www.tonystrackdays.com/ - program for beginners, sounds good.
http://www.nesba.com/ - a group that runs track days. Has a free "intro" session where you can ride for a couple of sessions in the morning.
http://www.teamdaemon.com/ - two track days a year at Loudon, looks defunct.
http://www.penguinracing.com/ - more focussed on instruction.

http://www.billnphoto.com/gallery/v/NHMS+sept+30/?g2_page=7 - pictures from a track day in 2009. I'm in black leathers with a red helmet.

http://www.mad-ducati.com/ShowPage2.php?PageName=zseNMllaQhcitWtecoeMr7krTfn671/0q1niSex.7pbyrR4yhtihHAgl4m7V25 - safety wiring a Ducati. Some track days require that you safety-wire the oil filter.