Answer
Yes. Any of the vector and raster layers that ArcPad supports, such as shapefiles and MrSID, can be added to a map with the StreetMap layer. The drawing order of the StreetMap layer is managed in the Layers dialog box, as are all layers.
Here are some tips to ensure the best results:
--To view data that are drawn below the StreetMap layer, individual polygon layers that make up the StreetMap layer such as States and Counties can be turned off in the Layers tab of StreetMap Options.
--When possible, the projection of added data should match StreetMap's projection: Geographic, WGS84. Although StreetMap data will be reprojected when necessary, the optimum performance is achieved when this is avoided and all layers are using the same projection.