My friend is using a Sidekick which is very popular among deaf people.
It has a lot of features that help the deaf such as instant messaging,
getting online to check maps to get driving directions. It also has a
GPS and 911 feature that you press a button and emergency service
will come and assist you. They can pinpoint exactly where you are.
If you see the photo I took yesterday of the relay service. You can use
this on the sidekick and be able to make a phone call. If someone calls
you using a regular phone or cell phone, the caller ID will show up so
you know who is calling and you can call them right back on the relay.