I would advise against getting dual lands or shock lands. First of all, they are only good in decks where players are running those colors. If we assume everybody runs a 2-color deck of randomly chosen colors, there's a 10% chance that this card would be at all useful to them. Terramorphic Expanse/Evolving Wilds, Shimmering Grotto, and Manalith on the other hand will be at least partially useful in any deck that runs 2 colors, and even more so in a deck that runs 3-colors. I'm not a drafting expert, but whenever I see a dual land in a pack it usually gets picked close to last, while the 3 cards I mentioned go more quickly because they are more widely useful.
Second of all, dual lands are pretty weak cards in draft. If you are given the choice between a dual land you want and a good spell, its almost always a better idea to take the spell. Dual lands are a mainstay in constructed because they are slightly better than basic lands, but in draft you need to get as much as possible of every pick, and you can't usually afford to spend one just to upgrade a single basic land.
Third, dual/shock lands just aren't very interesting IMHO. They don't add any new archetypes to the cube like a few Liliana's Caress or Spider Spawning potentially could, they don't really strengthen very many other archetypes, and most importantly, when you pick them, you don't get the amazing Hehehe, lets see if my opponents can deal with this! feeling that you get from picking an awesome card.
I would definitely suggest Terramorphic Expanse/Evolving Wilds and Shimmering Grotto because they are good mana-fixing cards in almost any deck. Manalith, Alloy Myr, Darksteel Ingot, and other any-color 'mana-rocks' could also be a nice touch. These will allow players to build flexible mana-bases without having to wait to get a land in the colors they need and should take up less space than a bunch of color-specific lands.
If you have a cube with a multicolor focus you may want to try the Shards of Alara tri-lands because they will be viable in more decks or even the signets. Neither of them are great, but they are both useful in more contexts than the dual lands.
user1873's list of Artifact Searchers should also be helpful. :D