I wonder what IDE do you use for your development?
I don't use any IDE. I used to use jEdit as a programmer's editor, but recently switched to Komodo Edit. That, a Linux bash prompt, and Android SDK tools like DDMS, and I'm happy.
Do you deploy your application to a device for testing? What phone do you use?
I have a T-Mobile G1.
As some of us not in the US, do you have any recommendation on what phone to pick as an alternative phone for developing Android application?
Buy a T-Mobile G1 off of eBay or some local equivalent. The ADP1 (Android Developer Phone) has limitations with respect to downloading copy protected apps off the Android Market that, for many people, make it unsuitable except for firmware development. The G1's I saw on eBay yesterday were all less expensive than the ADP1, and many were available for international delivery. So long as they are unlocked for you,
you should have no problems using them with an existing GSM SIM, though you may not get 3G access. 3G access is handy, but I don't have 3G service where I live, so it is certainly not essential for development purposes.