Which is faster? A 10/100 switch or wireless-n?

"That may depend on the distance between the WLAN adapter and the router, but the wireless connection can be faster than the wired connection:

100 Mbit/s wired LAN offers offers speed up to 100 Mbit/s or 12.5 megabytes per second.

With an 802.11n wireless you will get up to 300 Mbit/s in theory. The real-world throughput clocks in at 160 Mbit/s or faster which translates to 20 megabytes per second. At greater distance 802.11n networks can still operate at up to 70 Mbit/s, which is not bad, but slower than the wired connection.

If you want to do a site survey and map the signal strength (which is the crucial factor for WLAN speed) around your location I recommend Ekahau HeatMapper:

Ekahau HeatMapper is a free software
tool for quick and easy coverage
mapping of Wi-Fi (802.11) networks.
It's the only free, easy-to-use tool
that shows, on a map, the wireless
network coverage in your home or small
office. HeatMapper also locates all
access points.

HeatMapper also provides a real-time
view to all access points and their
configurations.

HeatMapper uses your built-in wireless
network adapter, therefore, all you
need is a Windows-based laptop with
wireless. And it takes just one minute
to install."

"An extra point to consider as well as those already mentioned (distance, interference, latency, : a wireless access point essentially acts as a hub rather than a switch so once you have more than one active transfer between machines on the wireless network the total throughput will fall due to collisions.

Collisions on the wireless side of your device will not slow down anything connected to the wired side though (unless one of the machines on the wired side is talking to a machine connected via wireless, or course, or the router is very badly designed)."