Build a foundation for students to succeed (vocabulary tools)...
Reach students at current levels of learning (student response systems, found digital resources)...
Develop a vault of worthy resources, and use them for: instant presentations, student learning resources, and professional development (social bookmarking/curating tools)...
Ensure students work harder than you do--and that they continue working until the objectives have been achieved (collaboration using synchronous communication tools, back channels, and formative assessment using student response systems)... Facilitate student rehearsal, application and transfer of new knowledge/skills (student response systems, vocabulary tools, Google Drive collaborations or presentations, back channels, real world applications, external partnerships)...
Have fun, and/or make the world a better place (using all of the above plus your infinite imagination applied to a handful of useful tools)!