Biellmann type Spins
Biellmann
The Biellmann spin is another variant of the upright position. Introduced by Denise Biellmann, this spin requires great flexibility. Starting in an upright spin position, the skater reaches back over her shoulders and grabs the blade of the free foot's skate, which is extended "up" towards the ceiling (the back and body of the skater remain upright too). Its kind of like doing a "splits" in a vertical position. This can be very impressive if the skater can get into position quickly and hold it a long time. It can also be very awful if the skater wastes three or four revolutions getting into the position, and only holds it for one or two once she gets there.
The Biellmann spin that Selena performs here (left) is actually the second part of a combination spin - she demonstrates a very nice quick transition from the camel position to the Biellmann position.
L-Spin
The spin that Selena is performing here (right) is similar to a Biellmann in the sense that it is in a splits position, but in this case her lifted leg is in FRONT of her instead of behind her. For obvious reasons, it is only performed by very flexible skaters.
Note that in the pictured spin, Selena is skating on her right foot, making this a back spin.
Generally skaters grab their blade or the back of their knee to help maintain this very impressive position.
Some skaters do not pull their leg into the straight up position shown here, but rather perform this spin with the leg sticking straight out in front, hence the name... (thank you to Kelly Yamagachi for giving me that name...)