The most important thing in a Android based smartphone is amount of internal memory. The internal memory is factor which will decide how many apps you can install on your smartphone. So for a smartphone to be quite smart, you will need at least 4GB of internal memory.
To my amazement, I have not read this single most important fact in any of the tech columns or reviews for any smartphone. As a result, I can conclude that most of the reviews are generally useless. In HTC Salsa, you get 150 MB of internal memory. From this 10-15 MB will be used by the contact information, the rest will be used for facebook, twitter, google maps, gmail & other essential apps.
For all other apps, you will have some 40 MB free. Angry birds the most popular mobile game requires 17MB.
In Android, from ver 2.2 onwards the apps can be installed on the memory card. But there is a catch to this. Not all apps can be installed on the memory card. Only if the app developer has provided the required permissions to move the app to the memory card, only then that app can be moved to the memory.
The next question arises, why the app makers don’t provide this basic & most important feature? One possible reason can be that the performance of the app can really drag if the micro SD card is of low memory speed like class2. Using a class10 memory card can solve this problem, only if the app developer has provided the feature to move the app to the memory card.
Another option to get around this problem is to "root" your phone. What is that ? This means that you get the root permissions on your phone & now you can do anything & move any apps to the memory card.
But if you root your phone then the warranty on your phone becomes void, do it on your own risk.
My suggestion is that you truly want to enjoy the various features of an Android based smartphone, please ensure that it has at least 4 GB internal memory. This will ensure that you ample of space for various apps. These days my HTC Salsa, every 3 days starting crying about low internal memory.
About other features like like facebook widgets is good & will be working as long as you have sufficient free internal memory. The camera is quite decent.
I bought it on flipkart, excellent website with great service.