www.google.com
Seriously, just use google.
Let's say you missed Top Gear episode 125 (just a made up example).
Search: "Top Gear" and "125" and "streaming"
Switch it around a little bit if that doesn't work to maybe:
"Top Gear" and "episode 125"
Or you can search the torrent titling like, "Top Gear S6E22" (season 6 episode 22, just another made up example)
Also, if you find a blog that posts streaming copies of whatever tv show you are looking for, bookmark it because in all likelihood they do it every week.
I don't even have cable anymore. I just have my laptop w/ an HDMI splitter hooked up to my tv and a wireless keyboard and mouse. I always have 3-4 windows open in different frames. That way I can "flip" between CNN, MSNBC, ESPN/ESPN2, and whatever I want to look up at that moment.