Boost WiFi signal strength w/ no access to the router?

You can extend it thereby expanding the Access Points used to connect to your network...

Its called an Access Point for WiFi Connections... you can think of it like a Wireless Switch...

Really hard to determine your problem so here are some tips.

If you have a lot of Wireless Signals in your area then use one of these channels 1 & 6 but not the others... by default All Wireless Routers are set to Channel 11 because FCC regulated it that way, because its the best channel to use.

This may bore you a little:

All of the versions of WiFi up to and including 802.11n (a, b, g, n) operate between the frequencies of 2400 and 2500MHz. These paltry 100MHz are separated into 14 channels of 20MHz each. As you’ve probably worked out, 14 lots of 20MHz is a lot more than 100MHz — and as a result, every 2.4GHz channel overlaps with at least two (but usually four) other channels (see diagram above). As you can probably imagine, using overlapping channels is bad — in fact, it’s the primary reason for awful throughput on your wireless network.

Fortunately, channels 1, 6, and 11 are spaced far enough apart that they don’t overlap. On a non-MIMO setup (i.e. 802.11 a, b, or g) you should always try to use channel 1, 6, or 11. If you use 802.11n with 20MHz channels, stick to channels 1, 6, and 11 — if you want to use 40MHz channels, be aware that the airwaves might be very congested, unless you live in a detached house in the middle of nowhere.

http://upload.wikimedia.org/wikipedia/commons/thum...

Yes and no. If you're using your laptops internal WiFi card and that card doesnt have an exernal antenna connector, then you still could attach an external WiFi adapter with a high gain antenna like e.g. http://www.amazon.com/Alfa-AWUS036NHV-9dBi-Magnet-...

Otherwise, if your laptop does happen to have an external antenna port, just the antenna might be sufficient: http://www.amazon.com/Alfa-Booster-OMNI-Directiona...