Armor sorted by source, not by slot. I'm offering suitable cloth and leather options as well as mail, since, well, you read the rest of the post. You know what I'm talking about.
There might be some Ulduar hard-more items in these filters, along with some class-specific items from Onyxia -- sorry!
From normal mode dungeons:
- Abyssal Rune is a fantastic ele trinket, and farmable to boot. Drops in Trial of the Champion.
From heroic mode dungeons:
- Nevermelting Ice Crystal is less desirable because it's not a proc, but still good if you've nothing else comparable. Drops in heroic Pit of Saron from Scourgelord Tyrannus.
- Pendulum of Telluric Currents offers a direct haste boost, which is valuable at this gear level. Drops in the Oculus.
- Mark of the War Prisoner is great for those in need of hit. Drops in the Nexus.
- Forge Ember is the quintessential crit + procced spellpower boost trinket. Just a really bad one. Drops in Halls of Lightning.
- Sundial of the Exalted, on the other hand, is pretty good, and purchasable with badges.
- Shard of the Crystal Heart is also a decent grab if you're lacking hit. Purchasable with badges.
- Talisman of Volatile Power has a whole bunch of crit on it. As with the Nevermelting Ice Crystal, it's less desirable because it's not a proc-based trinket. Drops from Faction Champions in Trial of the Crusader.
- Muradin's Spyglass drops relatively early in Icecrown Citadel, and from the easiest encounter (Gunship Battle) to boot. It's a fantastic trinket. You want it.
From tier 9 or higher 25-man raids (including Vault of Archavon):
- Reign of the Unliving drops from Anub'arak in Trial of the Crusader, and it's another highly coveted trinket among elementals.
- Dislodged Foreign Object is the current best elemental trinket in the game, and it drops from Rotface in Icecrown Citadel.
- Maghia's Misguided Quill is available with Frost badges, but it's an objectively terrible trinket unless you're in some strange situation where you're both not hit-capped AND swimming in Frost badges. Spend your badges on something good, like tier 10 gear.
Show your totemic mastery by reading Totem Talk, whether reading Mike Sacco's Elemental edition or Matt Rossi's coverage of Resto and Enhancement.