Microsoft has announced plans to launch a 512MB memory unit for the Xbox 360 and increase in the official size of limit of Xbox LIVE Arcade games from 50MB to 150MB.

The 512MB Memory Unit, available worldwide beginning April 3, 2007, will be pre-loaded with the hit Xbox LIVE Arcade game “Geometry Wars: Retro Evolved” from developer Bizarre Creations for a limited time.

Apart from offering gamers the ability to take data with them where they go, the 512MB Memory Unit also gives Xbox 360 owners the ability to download exclusive content from any of the 45,000 Xbox 360 kiosks accessible at retail outlets worldwide.

The 512MB memory card will cost $49.99 in the US with the original 64MB Memory Unit simultaneously dropping in price from $39.99 to $29.99 (ERP).

Also announced today is that the Xbox LIVE Arcade game size limit has increased from 50MB to 150MB, giving developers greater flexibility in game design and expanding the opportunity to add advanced game features while still keeping games compact.