Here are some easy promotional offers from credit cards that have helped me save for an early retirement! 
I regularly supplement my income and boost my savings rate by taking care of my credit and only applying for the most lucrative offers, like the ones below. Updated as of December 2011.50,000 Points, worth $500 in Cash or $625 in Airfare
The Chase Sapphire Preferred Card is a rewards credit card offering new cardholders 50,000 bonus points after you spend $3,000 in purchases within the first 3 months. This is quite a good deal, as 50,000 points can be redeemed for $500 cash or two airplane tickets worth up to $312.50 each (you can buy a more expensive ticket and simply pay the difference). No annual fee for the first year, $95 in future years. They also now offer 2 points per dollar spent on dining, and 1 point per dollar spent on all other purchases.(This card is the “big brother” of the regular Chase Sapphire Card, where you can get 25,000 points after you spend $3,000 in purchases within the first 3 months, and there is no annual fee in the first year or subsequent years.)
$500 in Gift Cards or towards Student Loans, Mortgage, Airfare, or Hotel
Two Free Nights at any Hyatt Hotel in the World
Do you like your rewards in the form of something especially luxurious? The Hyatt Credit Card by Chase offers the opportunity to get two free hotel nights at any Hyatt-affiliated hotel, which includes some of the best hotels in the world. You get one Free Night Award after your first purchase, and an additional Free Night Award after spending $1,000 in the first three months of account opening. The free nights are valid for a standard room at any Hyatt hotel worldwide, with no blackout dates, within one year of issuance. Award nights have no resort fees, no internet fees, and no redemption fees. The potential value of this reward is over $1,500.$250 in Amazon.com Gift Certificates, 30,000 Airline Miles, or Free Hotel Nights
The Starwood Preferred Guest® Credit Card from American Express is currently giving out 10,000 Starwood points for signing up and making any purchase, and if you spend $5,000 within the first six months you get another 15,000 bonus Starpoints. Introductory annual fee of $0 the first year, then $65 a year after that.25,000 Starpoints can be redeemed for hotel stays at Westin and W hotels. If you like airline miles, you can get 1.25 frequent flier miles per point, 25% more than other airline-specific cards. So 25,000 Starpoints = 30,000 miles. 25,000 points is also enough for a $250 Gift Card to Amazon.com, Gap, Nordstrom, Banana Republic, and more.
Chase Ink Bold for Business: 50,000 Points Worth $500 Cash, $625 in Airfare
Here’s another bonus worth $500+ for all you freelancers, consultants, and small business owners out there (even if you don’t even know it). The Chase Ink Bold with Ultimate Rewards is offering 50,000 bonus points after spending $5,000 in the first 3 months your account is open. There is no annual fee for the first year, $95 after that. Also earn 5 points for every dollar on everyday business expenses on up to $50,000 in purchases.Many people aren’t aware of the fact that they can apply for business credit cards, even if they are not a corporation or LLC. Why? Because any individual can be a business as well. The business type is called a sole proprietorship.