I'm one of those never-throw-the-toothbrush-out kind of people. When I'm done with them, they all go to the cleaning cupboard to be tiny scrub brushes. One time in high school I even made one into a bracelet. However, I cannot even recall the last time I decided I was going to clean something so thoroughly that I used a toothbrush to do so! Seeing as I'm not so good on the reusing front, and in general I'd like to lower my use of plastics (especially ones that aren't readily/obviously recyclable), maybe an alternative toothbrush would suit me. My husband found these, actually: the environmental toothbrush.
A dentist in Brisbane invented this toothbrush, which is made of bamboo. They're a bit basic, but last well and do the job just fine. Another bonus is the low cost. But I must say that as soon as I started using them I realised how many "comfort" design features regular toothbrushes have. Flexible neck, contoured head, etc...this brush does not have that. But I found out that although it was noticeable at first, in the long run I didn't care.