Hola
ciberpata
Prueba con esto:
<td onMouseOver="this.style.background='#f0f0f0'" onMouseOut="this.style.background='#ffffff'" onclick="window.open('http://www.viajealacarta.com/destinos.asp?id=<%=http://url.com%>')" style="cursor:pointer"</td>
Saludos,
