There are only two motorboards that one can think about using with public transportation: Roth's 2000XR and Go-Ped's I-Ped introduced in 2009. Even Roth's 16+ pounds (actually more like 20pounds) is just bearable. The I-Ped's 32+ pounds is too much. Also I-Ped's design is not as good as Roth's, poorly balanced, awkward motor, hot heat dissipation fins, and important in a public setting - lack of a "cool" look.
But the worse part is its price. a2bscooters.com says "Introductory Sale on I-Ped 8 for $1399 While Supplies Last! After Will be Priced at $1699. I-Ped 16 will likewise go up to $1999!" $2000 for a scooter!?!?! I bought used cars for less. I think an electric scooter should be priced like a motorized bicycle, say in the $300 to $500 range.
Roth's biggest problem was an unfinished drive mechanism and poor support. Well, with DC motors having a MTBF of about 3 years without servicing and LiIon batteries a life of 3-5 years - I would rather support the scooter myself, just like I would fix my own bicycle. As for the unfinished drive mechanism, I think with a little creativity and a few modifications could make the 2000XR the most awesome commuting scooter on the planet.