Are there any photographs of mountains without significant erosion (on Earth or otherwise)
Here's how astronomers of the late 19th century thought the Moon would appear:


Recreations in Astronomy by H. D. Warren D. D., published in 1879, via http://en.wikipedia.org/wiki/Selenography.

Here's what Apollo 15 astronauts saw:




  Apollo 15 Lunar Module Falcon at the Hadley-Apennine landing site. Hadley Delta in the background rises approximately 4,000 meters (about 13,124 feet) above the plain. The base of the mountain is approximately 5 kilometers (about 3 statute miles) away.


Source: NASA, from Four Out of Six Apollos.

Below is a photograph of the even taller Mons Hadley, 1.1 km taller than Hadley Delta shown above:


Source: NASA, photograph as15-86-11603, from Apollo Imagery. 

Compare the above with mountains on the Earth. Here's a picture of Mont Blanc, a mountain here on the Earth comparable in size to  the smaller of the two lunar mountains portrayed above:


Photograph by Zoharby, taken from Wikimedia Commons, licensed under Creative Commons Attribution-ShareAlike 3.0 Unported license.




  Alternatively, are there any mountains on Earth where (for whatever reason) erosion hasn't played a big role in shaping them so far, and which therefore look similar to the uneroded mountains one would find on an airless world?


Nathaniel, you have a mistaken view of erosion. Erosion eventually does tear the tallest mountains down to tiny little hills. However, erosion also makes those tall mountains very jagged at first. Erosion is the primary reason why Mont Blanc and other new, tall mountains are so jagged. Liquid water seeps into cracks in the rocks and then freezes into ice. Ice has a lower density than water. This means that liquid water expands upon freezing. That expansion breaks the rock that form mountains into jagged edges.

Another reason our mountains are jagged is plate tectonics. The Earth is the only body in the solar system that exhibits plate tectonics. New continental crust forms largely from older continental crust. Erosion eventually brings particles torn from mountains to a flat area or river delta, where they collect. The material brought to those collection areas changes over time. The end result: Strata (layered rock formations). The different strata in rock have different strengths and weaknesses and thus erode differently. That differential erosion results in jagged mountains.


Bottom line: You don't see jagged mountains on the Moon or Mars because they don't have water in all three phases and because they don't have plate tectonics.