I've been reading JH Collins' book, upon recommendations from this and another forum. I really like it. I already have an IRA with Vanguard, and am considering investing more with them. I also have my 403(b) with TIAA-CREF.
In the book, Collins recommends that if your employer-sponsored program features Vanguard funds, to invest in them. I had NO idea--but I checked today and lo and behold, my plan DOES! In fact, I only found out through a proposed reallocation report that the CREF rep prepared for me in case I want to take more risk in my investments. I'm a bit embarrassed to admit that I never really looked into my current plan (which is a Target Fund for 2030 in Social Choice) b/c I figured it was just too much trouble/I wasn't smart enough to understand anything about investing, so best just leave it alone with moderate risk investments.
So now I will have a chance to invest in Vanguard Index Admiral, as well as some others. I'm pretty excited about this!