As an unabashed fan of all things steampunk, here are some things other fans of the genre should take a looky look at. Feel free to add your own suggestions.
"Steampunk" Comic/Graphic Novel
by Chris Bachalo and Joe Kelly
The tale of Cole Blaquesmith and his revolutionary adventures in the Absinthian Empire of London. Unfortunately, only 12 of the planned 24 issues made it to print. Act III is lost to the ether. Still a very satisfying and artistically stunning series. I was lucky enough to find all 12 issues and the prologue as a set for only $10. The trades are available online or your local comicshop.
www.sillof.com
Wonderful website that displays steampunk versions of all your favorite Star Wars characters. Truly amazing.
All I can think of at this late hour... there are other things out there but are mostly shops that I don't want to/can't advertise for.

The Girl Genius is also good web comic to read. It has it all, mad scientists, weird inventions, all kinds of steam work and clock work aparatuses, monsters, adventure, romance, you name it.

Not a connoisseur of Steampunk, but I'd like to add my own recommendation. The Thief series has what I believe counts as a Steampunk setting, and especially The first sequel is one of the best games ever made imo. Fantastic stealth game.

While definitely not overall a steampunk game, Metroid Prime 3 on the Wii has an amazingly beautiful steampunk setting in one of the levels (Skytown, IIRC). Some of the sights are pretty breathtaking there.

Sadly you won't get as good a gaming fix of steampunk candy as Arcanum. Its just not a popular enough setting.
Chrono Trigger and Nostalgia on the NDS are fun but obviously not as true to the classic steampunk setting. There is a thief mod for Doom 3 that is worth checking out.
There are a lot of books in the genre but I've hardly read any myself. I did enjoy the 'Hungry City Chronicles' (known as the Mortal Engines Quartet in the UK) though, which is a bit of a mish mash of steampunk/post apocalypse.
I don't know if Larklight is still being made into a movie but the trilogy is a fun read for 'young adults' (and old adults too).
The Dark Mod (Doom 3 required): http://www.thedarkmod.com/
Hungry City Chronicles: http://en.wikipedia.org/wiki/Hungry_City_Chronicles
Larklight: http://en.wikipedia.org/wiki/Larklight

A couple more interesting additions that I forgot about the first time around:
Kenneth Oppel has authored a line of books about a young cabin boy who serves on a luxury airship larger than the Titanic. Airborn, Skybreaker, and Starclimber. I've read the first two, and even though they are aimed at the "young adult" crowd they are still pretty entertaining. [url=http://en.wikipedia.org/wiki/Airborn_(novel]http://en.wikipedia.org/wiki/Airborn_(novel[/url])
Then there is the PS2 game by the name of Steambot Chronicles. Follows the classic JRPG premise of amnesiac teenager off to save the world. The great thing is the sandbox style world in which you travel in and combat other steam powered mechs while making a living as an up-and-coming folk singer (yeah, I know). Combines great combat and rhythm based music minigames. Definately a "try before you buy" game, but I think its awesome. Sidenote: There is a great sidequest in which you actually invent the electric guitar. http://en.wikipedia.org/wiki/Steambot_Chronicles