What are some advantages and disadvantages of the 'first-past-the-post' electoral system?

Under first-past-the-post (FPTP), as practiced in the UK, each constituency elects one MP by what is called plurality voting. This means, more or less, that the candidate with the most votes wins. One advantage of this system is that it is simple to understand and therefore does not need to be explained to voters. This is in contrast to some other systems such as STV, which requires voters to rank a large number of candidates, and employs a relatively obscure method of picking the winning candidates based on these preferences. Another advantage of FPTP is that it provides a strong MP-constituency link, with one MP devoted to the needs of a particular geographical area. This can be contrasted with the closed or open list proportional systems, which can have many representatives per constituency. In Israel, for example, the whole country is one big constituency. 
A disadvantage of FPTP is that it is not proportional, that is, parties' number of seats in the legislature do not accurately reflect the share of the popular vote in the election. FPTP tends to be biased towards bigger parties which can get more than 30% of the vote in a lot of constituencies. In 2005, the Labour party won a sizeable majority in the House of Commons with only 35.2% of the popular vote. Advocates of FPTP argue that this is actually a virtue of the system, as it allows for strong majority government even when no party commands majority support in the country as a whole.