As you may or may not know, Android 2.2 added the ability to officially install your apps onto your SD card. No longer are you limited by the internal memory of your phone, but instead by the greater (usually) capacity of your SD card.
Well Tim Bray has posted an article by Suchi Amalapurapu, an engineer who worked on this feature over on the Android Developers blog. It’s a fairly technical read aimed at developers, but there is a useful paragraph on the positives and negatives of installing apps to your SD card:
“The advantage of installing on SD card is easy to understand: contention for storage space is reduced. There are costs, the most obvious being that your app is disabled when the SD card is either removed or in USB Mass Storage mode; this includes running Services, not just interactive Activities. Aside from this, device removal disables an application’s Widgets, Input methods, Account Managers, Device administrators, Live wallpapers, and Live folders, and may require explicit user action to re-enable them.”
[via android dev blog]