The G1 Google phone comes equipped with a 1GB memory stick. This is less memory than most users will want, so it pays to purchase additional memory now instead of later. The G1 Google phone is able to be upgraded to use 16GB of memory. Look at your current mobile habits to determine what capacity of Google phone memory cards you will need. Favor JPEG photo storage? Keep in mind that 1GB of memory will be able to provide storage for about nine hundred photos…
1GB of memory can also store about 250 songs. 4GB of memory can store several full length movies. With an 8GB memory card you could store several movies, nearly two thousand JPEG photos, and about 500 songs.

The Nexus phone comes with 4GB of memory, expandable up to 32 GB of memory. So that is definitely an improvement. Still, most people will purchase additional memory cards for the G1 and Nexus phones.