High Voltage Cable Inspection on 0.5MV lines. Thanks for all the comments! This is what I used to do a couple of years back, and that also it is shot so nicely, that I thought it befitting to show all.

UPDATE.
I have received a ton of requests regarding this video - mainly about how to get into the job. Well, the only way is to start at the bottom by becoming a trainee linesman with a power company. It is essential to have an understanding of Electrical engineering so a degree in this subject is a must have. You will have to work yourself up the ladder, demonstrating an understanding of risk and safety aspects, but most of all an ability to always be relaxed around all electrical distribution systems. Spider says it very well - "... it is not a job for a hot duck".

After working you way up the ladder and proving yourself, the training can be intensive and laborious, and after many experiences in a laboratory setting having experienced the feeling of high voltage passing around you and learning to identify what feels right and wrong, you can go and train for your certification for EHV transmission systems. After this, it is more training which continues until you are experienced enough to teach the next generation.

Yes - it can be considered dangerous in several ways. In the words of one of my mentors, "You will only make a mistake once Simon".

Some quick answers -
Suits - Made by DuPont to application specific requirements.
Pay - GBP40-70k dependent on experience, certification etc
The two lines are at the same potential in the video carrying one phase at 500kv
Lines go up to 765kv, but there are plans to go as high as 925kv from what I read (I am not in this business any more). Although there are lines working at over 1MV DC.
You cannot get life insurance.
It is not as glamorous as it appears.
For all the people who posted technical questions - do not believe everything that is posted as comments (although some is correct). The arcing between helicopter and line is the helicopter becoming the same potential as the line (air is the dielectric whos insulating properties break down when an object at zero potential comes within the break down point and is potential dependent), remembering that the line voltage is passing through 0v 100 times per second (or 120 times per second if you are on the other side of the Atlantic) meaning that the arc is struck that many times until the potential is equalized through the rod or bonding clamp.
500,000v is the phase to phase potential, whereas the phase to ground potential is around 288,600v.

Clip is from IMAX documentary called "Straight Up", and grabbed from HD source.