MCI offers a new plan called MCI One Net Savings. Summary and direct URL below. Requires an online account. You have a choice of 7 or 8 different frequent flyer programs when you sign up. I chose OnePass, so the details are below.

Not a bad deal at all - 9 cents Monday-Saturday and 5 cents on Sunday. No fees, but you need to spend at least $5 month.

Here is the summary they e-mailed me.

MCI One Net Savings:
State-to-state long distance calling for only 9 cents a minute all
day Monday through Saturday and 5 cents a minute all day Sunday.
Instate rates vary by state.

MCI Card Calling:
Call home for 5 cents a minute on Sundays and 10 cents a minute all
day Saturday and weekdays from 7:00 p.m. to 6:59 a.m. when you call
within the U.S. 25 cents a minute on all other calls home and 45 cents
a minute on all other U.S. calls.

MCI/OnePass Program:
2,000 bonus miles for signing up for long distance. 1,000 miles when
you use your MCI Card within 30 days of signing up. 1,000 miles for
signing up for MCI Internet. 5 miles per dollar spent, excluding
taxes and credits

Instate Local Toll Calling:
Great low rates on all your local toll calls.

https://www.mci.com/cgi-bin/WebObjects/NetSavings

I signed up with MCI but I have not yet received my bonus miles. I hear conflicting statements from their reps whether the internet rate of 9c/m qualifies for the bonus miles. Its been almost four months since I
signed up.

I signed up for this promotion a few months ago as well and have been earning mileage for my calls at .09/minute.

My only complaint is that you are restricted to using email to reslove any billing errors; a process that takes much longer than actually talking with someone.