Take a hard look at the fees the funds/plan charges, some of them are up to 2 or 3% for some of these "buddy" plans. Open a vanguard or fidelity fund and get your money into low fee index funds (vanguard if at vanguard, fidelity spartan if at fidelity). If there is no match and especially if the funds are high fee, put money into the vanguard/fidelity IRA first, then into the Simple (up to another 12k).

If you are at a low marginal income tax rate think about opening the new ira as a roth.

I like Vanguard. Low fees, easy interface, helpful employees.

I'm able to put money into a Simple IRA through my work to a fund company that my employer "recommends". He doesn't match it, but my contributions go in pre-tax. I'd like to put my dollars somewhere else where he doesn't have access to it/isn't friends with the fund money manager. Should I just open an IRA through Vanguard or USAA or something else? I'm ready to start saving more aggressively than I have in the past.