What's blooming in the woods? part one

Here are pics of some plants in the wooded area I'm trying to take back from the Japanese stilt grass. The only flowers I can identify are the cardinal flower with the Elephantopus Scaber in the foreground.
# 1 and 5 are the same flower.
# 3 and #4 are mystery plants.

Photos #1 and #5 look like indian tobacco, Lobelia inlata-

http://plants.usda.gov/core/profile?symbol=LOIN

http://plants.usda.gov/java/largeImage?imageID=loin_002_avp.tif

The other plant is either a stinging nettle-

http://plants.usda.gov/java/largeImage?imageID=urdi_006_ahp.jpg

or a false nettle-

http://www.illinoiswildflowers.info/woodland/plants/false_nettle.htm

Thanks Kate! I thought that little purple flower looked like a lobelia, but I couldn't find any photos of it online or in books. The pictures of the nettles are not of the same plant and, after looking at the links, I believe one is a false nettle and the other perhaps a stinging nettle. The leaves look different to me. There are a lot of those along a path in the woods, so I think I'll try not to brush up against any of them.