If you crack open a halogen parabolic bulb, you will find a small halogen tube just like you you find in the work light but smaller, in essence the parabolic bulb around it is actually an enclosure trapping heat and potentially shortening the bulbs life... I would also advise against dimming them as it will cause them to run too cool, see the link at the bottom of the page for an explanation of why this is bad for halogen bulbs...
My local dollar store has no shortage of regular bulbs and I have seen them return to many other local stores as bottom shelf items once people actually read the US law and saw that the prohibition only applies to consumer lights used for general illumination... Specialty bulbs, commercial use bulbs, rough use bulbs, decorative bulbs, plant lights and a slew of other exemptions are listed in the law, the bulb manufactures just had to re-label them for a different uses to get around the prohibition and many manufactures have done just that recently... Of course many retailers like the higher profit margins of florescent and LEDs and are reluctant to bring back the traditional bulbs and will tell you they are outlawed even though that is technically a fib or they didn't read the law clearly...
There is also no shortage of online websites selling them now since many local stores stopped carrying them... There are even whole new startup companies like this
http://www.newcandescent.com/ dedicated to selling old style bulbs...
The halogen bulb is the small glass tube not the faux glass dome around making it look like traditional bulb, the tubes are small by design as the halogen bulbs have to reach a higher temp and run hotter to perform the halogen cycle properly, and the glass has to also be a higher temp rated glass to handle the heat... The smaller physical size with the same heat generation creates a higher running temp...
Scroll down to the halogen bulb section of this site for a far more detailed explanation...
http://donklipstein.com/bulb1.html