Mashable readers: Welcome to the best blog on redeeming frequent flyer miles. The way that I've traveled to over 20 countries this year and spent nine months abroad is by signing up for credit cards and using the miles to book business and first class awards.

Here is a post that explains to beginners what I do and why I do it.

Mashable readers: Welcome to the best blog on redeeming frequent flyer miles. The way that I've traveled to over 20 countries this year and spent nine months abroad is by signing up for credit cards and using the miles to book business and first class awards.

Here is a post that explains to beginners what I do and why I do it.

There are currently four stackable promotions related to US Airways miles.

Barclay's is offering US Airways Premier World MasterCard holders up to a 50% rebate on redeemed miles between and November 30, 2013 up to a maximum of 30,000 rebated miles!

This is an incredible deal, and complements Monday's Share Miles deal that I called "the best opportunity to buy miles all year."

Are you eligible for a 50% rebate on your US Airways awards?

US Airways emailed me the following yesterday:

It's some slick marketing, but I won't be taking advantage of any of the "new" benefits. I have a US Airways Premier World MasterCard, so you'd think I'd be excited, but I'm not.

Why won't I be taking advantage of any of these generous-seeming new benefits? Let's go through the "additional travel benefits":

Zone 2 Boarding and First Class Check In: While nice, these aren't new and have been benefits of the card for a while.

Speculation is running rampant that US Airways will join oneworld November 1. The most recent fanning of the flames came from a post on FlyerTalk purporting to rely on an internal memo to US Airways employees.

Then View From the Wing pointed to this article quoting J.

The US Airways Premier World MasterCard is offering me 5 miles per dollar at grocery stores, drug stores, and electronic stores for the next three months via a targeted email. Check your inbox for the same or a similar offer.

What offer did I get?

I just got the following email:

I quickly clicked the Activate button and got this message:

It seems like the US Airways Premier World MasterCard is constantly running promotions.

Update: Several--if not all--of these offers have expired.

The cards mentioned in this post have had their links removed because the offers listed have expired. Click here for the top current credit card sign up bonuses.

The 50k mile bonus offer is back on the Lufthansa card mentioned in this post until 6/30/14.

Update 1/17/14: 35k offer is dead, but the 40k offer is alive!

FlyerTalkers are reporting success getting a 35,000 mile bonus and no annual fee for the first year on the Barclay's US Airways MasterCard.