E-mail

• Most common form of text communication

• Both desktop and mobile

• Store and forward -- delay

Commercial instant messaging

• Widely used, generational shift

• Both desktop and mobile

• "Presence" lets you know who is online

• You control whom you will talk to

• But not standardized

• Line by line format

SMS and MMS

• Mobile phones, growing use

• Text messaging standardized across carriers

• Latency, lack of delivery – not intended for emergency

• But used in UK for deaf mobile access to 9-1-1