Apple's special edition "Red" iPod Nano recently got a significant capacity increase. The tiny player, supported to endorse an AIDS campaign, can now be equipped with up to 8GB of storage space and still maintain high battery life. The devices are priced pretty much in line with any other iPod product based on their size and capacity:

The new model of the iPod Nano (Product) RED Special Edition holds up to 2,000 songs, and joins Apple's 4GB model. The devices are sold for $249 and $199, respectively. Both devices come in red aluminum cases and feature 24 hours of battery life. Apple contributes $10 from the sale of each product to the Global Fund to Fight AIDS in Africa.
Regional availability wasn't mention, so you can assume that if you have access to the other Red Nano's you'll have access to these newer ones as well.