I hate losing or slowing down of my Internet connection.
This is one easy way out.
Materials: 8 pieces of wood, 4 screws, a computer fan, glue
Tools: miter saw, drill, screwdriver
1. Cut 4 triangular pieces of wood that fit the corner of the fan. I will refer to these as "corner pieces" from now on.
2. Drill mounting holes on the corner pieces to fit the fan, make sure airflow is not severely impeded by them
3. Cut 4 stands, that will raise the fan a distance from the surface it will be on. Sufficient height is needed to get a volume of air underneath that can be pushed up
4. Glue the triangular pieces to the stands
5. Mount the fan with four screws. Make sure it is facing the right direction. In this case, we want the air blowing upwards.
6. Place the modem or router on top, and enjoy.
This works well if your modem/router has vents only on the bottom side like mine. You might want to consider a different design otherwise.