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

Dental Care Transaction
Sale: Reach: Total Care Toothbrush or Floss, 30 yds, 2 pack advanced design toothbrushes. Listerine: 72 ct. Pocket Paks, Total Care or Advanced Mouthwash, 8.45 oz. Limit 3. 3/$9
Get: (1) Reach 2 pack advanced design toothbrushes, (1) Reach Total care Floss 30 yds, (1) Listerine Pocket Paks 72ct.
Use: (1) Reach Toothbrush or Value Pack, any $1/1 (5-31-10) SS-6/14. (1) Reach Dental Floss, any excluding trial sizes or any Reach Access Flosser $1/1 (5-31-10) SS-6/14. (1) Listerine Antiseptic, any 500 mL or larger or any Plax Rinse, or any Efferdent 78 ct. or larger, or any Listerine PocketPaks 24 ct. or larger or any Listerine PocketMist .50/1 (5-31-10) SS-6/14.
Use Store Coupon: In Ad Instant coupon (back page) $5.01/3
Pay: $1.49

Cold Care Transaction
Sale: Vicks, 10 or 20ct Nyquil or dayQuil or liquid, 6oz. VapoRub 1.75 oz. $4.49
Use: 5x Vicks NyQuil or Dayquil, any $2/1 (2-28-10) PG-1/17 (if your not getting nyQuil/ DayQuil use Vicks Product, any except NyQuil or DayQuil $1/1 (2-28-10) PG-1/17 )
Pay: $12.45 + tax
Get: $10 rr from Vicks

This is a good deal when you think that your paying $13.94 for 5 bottles of Nyquil, toothbrushes, Listerine and floss AND walking out with $10.

If you have any questions about how Register Rewards work go here for the answers.