Any good tips for overclocking memory?

I'm running a pair of these

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231468

Rated for 2133 now at 2400. Any ideas on possibly getting them to 2600?

If your timings are already 12-12-12 then I doubt that you can make 2600+. You can try with higher dimm voltage and VCCIO but I'm not sure how much you really need on IB to make it work @2600. If you can pass spi32m then maybe you will make next 100MHz. Try something like 11-13-12 ~1.7V.
If you want some more help then it will be good to show full timings table. It can be window from AIDA64 or if you have ASUS/ROG board then memtweakit software ( can find it or googling or in asus/support page and ROG X79 boards, I haven't seen it in Z77 download section ).
CPUZ SPD window isn't good as it's showing only base timings in XMP 1.2 revision. Memory window is showing only main timings and not even all as tRC won't be visible on Intel boards.
Simply since you reach CL12 then you don't have much more space for main timings and you can only play with some subtimings. In this case it will be hard to help as you hit almost max for main timings.

Woo

Thanks for the advice. I tried everything and 1200 is as fast as she'll go but after playing around for awhile she'll do 1200 on 1.55v