Here's a quick little thought experiment: in what environment would the card Tinker be the most fun? If you could build an environment specifically to make tinker a really fun spell to cast, what would it look like?
I just added Tinker to my cube. The reason I added it was because I recently had taken out the last stupid tinker target: Myr Battlesphere. Tinker IS a fun card.
Tinker is fun in the same way any tutor is fun: its lets you build a toolbox of answers or act as a second copy of your best card. Tinker is not fun when it brings out a card way earlier then it is supposed to.
I don't think there is any reason to build an environment specifically for tinker to be really fun. You just need the following:
1) A variety of artifacts that can answer problems or create threats
2) A variety of artifacts that are cheap or have temporal value
3) No huge artifacts that can win the game by themselves
These goals are pretty easy to attain. How much value are Wurmcoil Engine, Sundering Titan and Myr Battlesphere REALLY adding to your drafts?
Those, along with Memory Jar, are the perfect Tinker targets if you don't want the card to cause blowouts IMO. There's also Triskelavus if you want something that mimics Battlesphere without being as unbeatable. How about Akroma's Memorial? Obelisk of Alara? Contagion Engine if you want to support some trickier subthemes.
I like the Triskelavus suggestion, and along those lines, Triskelion and Grim Poppet might be suitable too. Steel Hellkite is an option, though it might be slightly underpowered. Spine of Ish Sah is there if you want to go really deep.