Heres a few transaction scenarios for you, you can also check out the walgreens thread for more great ideas.

Transaction #1
Sale: Natures Bounty Vitamin D-1000 IU 120 ct Tablets $5
Buy: 1x Natures Bounty Vitamin D-1000 IU 120 ct Tablets
Use: -Natures Bounty HERE (gave me a $2/1 just for signing up! And it let me print 4)
Pay: $3 +tax
Get: $5 Register Reward

Transaction #2
Buy:1x Colgate Total Advanced or Enamel Strength Toothpaste 4 oz or Wave Toothbrush $2.99
1x Kotex U Ultra Thin Pads 14 to 18 pk, Pantiliners 50 or 60 pk or Tampons 18 pk $3.49 (2.5rr)
1 filler item equaling at least .27 (a filler item is just a cheap item to either bring your total after coupons up so you can use a register reward, or to make it so you have as many items as coupons)
Use: There are a few coupon options out there-
Colgate: Colgate Total Toothpaste .75/1 HERE
Kotex: Kotex U Products $1/1 HERE
Kotex U Liners, Any $1/1 (5-30-10) SS-4/18
Kotex U Pads, any $1/1 (5-30-10) SS-4/18
Kotex U Tampons, Any $1/1 (5-30-10) SS-4/18
Use Register Rewards: $5 from Transaction #1
Pay: Tax
Get: $2 register reward for Colgate and $2.50 register reward for the Kotex.

I plan on rolling into another Transaction #1. Useing the $2 coupon for signing up with Natures Bounty and the $2.50 register reward from Transation #2 I’ll just pay .50 +tax and get $5 back! If you dont want a zillion Vitamin D tablets you could roll between the toothpaste and Kotex. Heres how:

Alternate Transaction #1
Buy:1x Colgate Total Advanced or Enamel Strength Toothpaste 4 oz or Wave Toothbrush $2.99 (2rr)
Use: Colgate Total Toothpaste .75/1 HERE
Pay: $2.24 +tax
Get: $2 Register Reward

Alternate Transaction #2
Buy: 1x Kotex U Ultra Thin Pads 14 to 18 pk, Pantiliners 50 or 60 pk or Tampons 18 pk $3.49 (2.5rr)
Use: Kotex: Kotex U Products $1/1 HERE OR
Kotex U Liners, Any $1/1 (5-30-10) SS-4/18 OR
Kotex U Pads, any $1/1 (5-30-10) SS-4/18 OR
Kotex U Tampons, Any $1/1 (5-30-10) SS-4/18
Use Register Rewards: $2 from Transaction #1
Pay: .49 + tax
Get: $2.50 Register Reward

Questions about how Register Rewards work? Go here for the answers.