I have myself an XPS m1710 with a Geforce Go 7950 GTX, and it is heating a lot, especially due to shader effects. When I say a lot, I mean that GPU regularly reaching 92, 93°c for some graphically heavy games. (edit: 97°c today, new record).
Cooling pads are a good idea, it helps, but not all of them are effective, especially if you have separate fans which are not pointing on the appropriate places under the laptop (most are made for laptops without fans, so it doesn't really matter where it goes). I use a Notepal Infinite, it is quite nice because it's all the surface which is cooled down, not only precise points.
However, it helps only, as no cooling pad has the correct access to the heating place. At best you cool down the bottom, simply, so part of the heat is taken away, but that's all.
Cleaning the fans area helps, if you notice an increase in the temperature over the time. Dust easily gets into the heatsinks, and prevents correct cooling down.
Besides, keep in mind that laptops are not really good at taking heat away for some graphical cards, compared to desktops (which is normal according to the thin shape). If it stays at max 85, then it should be ok. Graphical cards are resistant to heat, and have several safety mechanisms. If it goes too hot (I think mine starts that past 90 something), it will first force the GPU frequency to lower, like if you were on battery. If this is not enough and your card reaches dangerous levels, it will trigger an instant shutdown.
If you haven't experimented such safety measures, or graphical artifacts (which tend to happen on high temperature: black textures, disappearing polygons) yet, it means you were on a correct temperature, in my opinion.