-------------------------------------------------------------------------------
Ploting Tubes in Mathematica..

<<LinearAlgebra`Orthogonalization`
tubeplot[curve_List, range_List, radius_] := Module[
        {perps, var=First[range], theta},
        perps = GramSchmidt[NullSpace[{D[curve,var]}]];
        ParametricPlot3D[Evaluate[curve +
          radius*Transpose[perps].{Sin[theta],Cos[theta]}],
          Evaluate[range], {theta,0,2*Pi}, PlotPoints->50];
        ]

Here is the example from the original post.

curve1= {t,Sin[t],0};
tubeplot[curve1,{t,-5,5},1]

Here are two examples that have tangents that vanish at a point in the
parameter interval. This is noticeable in the plot but not easily
avoided (and also it is not disasterous to the picture). One can make
the "pinched" regions small by upping the PlotPoints but this tends to
make the process rather slow.

curve2 = {t+1-Exp[t],Sin[t],0};
tubeplot[curve2,{t,-2,2},.3]
curve3 = {t-1-Log[t],Cos[t*Pi/2],0};
tubeplot[curve3,{t,.1,4},.2]

-------------------------------------------------------------------------------