Hey,
I dont know of a single tool/command off hand that does it but under the polygon subset there's the selection menu.
"grow selection" followed by "selection boundary" generates something similar
theres also the "Convert Selection" options too. You can issue those in a mel script to get identical functionality and place that in a shelf button etc.
ie:(with a vertex selected)
//vertex to adjacent vertices
string $initSel[] = ls -sl -fl
; //finds initial selection
ConvertSelectionToEdges; //changes selection to all edges that include that vertex
ConvertSelectionToVertices; //changes selection to all vertices included by previous edges
select -d $initSel; // removes initial vertex selection
-Beast