Glyph of Elemental Power and Signet of Fire both give the possibility of setting an enemy on fire a good fraction of of the time. Signet of Fire probably does that more efficiently, but that's all it does; GoEP has alternative benefits as well, namely your choice of Weakness or Cripple. Of course, it's easy to "over burn" as an elementalist -- and even more so for me, as I'll be duoing with another one.
Arcane Blast and Power Wave do probably lesser damage, but they always work, and they're combo finishers. Probably good to practice with for later use in PvP.
Frankly, all four of those seem like they're worth a skill point each to give one the option of equipping them.
That's about as far as I've gotten.
As for later on -- I've never taken Signet of Water in an sPvP build, but I suspect it might be good at the mid levels in PvE before I'm fully traited for condition removal.
Edited by FrancisCrawford, 23 July 2012 - 07:25 AM.