Quote fromA WHEEL? Are you forgetting the FIRST rule of Minecraft?: No circles
but I like the wheelbarrow
I apologize for the coincidental obsenity of the following but my response to your "First rule of minecraft" requires it.
*Cough* SnowBALLS *Vomit* SlimeBALLS *Upchuck* GhastBALLS *Censored* Creeper#@%% *CENSORED*
You would have to have no BALLS and use no BALLS (which are currently useless btw) to defy the minecraftiness of Spheres. If you have ever played SMP you have surely been hit by snowBALLS at least once!
And let us note that RECORDS ARE CIRCLES!!!!!
...now, on to business. Wheels are useful for not just wheelbarrows and looms, but also:
rotating blocks (for rotating trusty pistons, dispensors, bridges, etc)
pushable carts (propelled long distances by pistons and the like w/o tracks)
fans (shoot air that pushes mobs)
turbines (produce power if water [or lava if iron turbine] flows through)
fans part 2. (increase/decrease water flow while powered)
fans part 3 (moves water/lava blocks to other side of fan)
pulleys (pull/let out rope when powered)
accelerator blocks (increase forward momentum of mobs and blocks, not just carts like current boosters)