Depends on how far away from work you live, and what type of road you want to travel on.
If you only need to travel about 25 miles a day, something like a Xebra may work. It is a 3-wheel electric car that is licensed as a motorcycle, so it doesn't have NEV (GEM, etc.) 25 MPH speed restrictions. They go about 40 MPH tops. On the bad side, they are built in China and have some quality control issues.
For now, there aren't any inexpensive (or at least comparable in price to a cheap new car) freeway-capable vehicles being produced. As mentioned by others, if you are mechanically inclined you can do a conversion for about $5000 or so. (using a car you already have).
There is a thread on ecomodder.com about a $672 electric conversion, but you'd have to be fairly resourceful (and lucky) to find all the parts that cheap.
Occasionally, used 'commercial production' electric cars (typically Ford Escort - size cars professionally converted) come up for sale. Many of these can go 65 MPH or so, and may work for you if you need freeway speed.
As an aside, I wonder about the claims regarding natural gas (and hydrogen) that pop up from time to time. Assuming the 2-stroke motorcycle gets 50 MPG on gasoline, it would take two gallons to go 100 miles.
2 gal gasoline = 250,000 BTU (125,000 BTU /gal)
1 cubic foot of natural gas = 1030 BTU (approx)
242 cu ft natural gas = 2 gallons of gasoline.
A typical scuba tank is about 10" in diameter, about 3' tall and holds 80 cubic feet when pressurized to 3000 PSI. (that's three THOUSAND psi...)
3 scuba tanks @ 3000 PSI would contain about 240 cubic feet. If you used low pressure tanks (such as old Freon bottles) you would have to use about 40 six cu ft tanks @ 100 psi. (one hundred psi)
Questions - How does Sally Compost manage to:
Gather 242 cubic feet of methane (natural gas) from her compost heap?
How long does it take? (a manure digester -type system using a 50 gallon drum makes about 5 cubic feet of methane a day)
How does she compress the methane to 3000 PSI? JC Whitney doesn't sell high pressure flammable gas rated compressors...
Where does she strap the -three- scuba tanks onto a 250cc motorcycle?
Many 2-stroke motorcycles use oil mixed fuel - difficult to mix oil with methane... Could use oil injection perhaps.
Beyond that, street-legal 2-stroke motorcycles haven't been sold in quite a few years due to air pollution concerns. 2-stroke and 'clean fuel' don't add up.