One colleague, years back, got somewhat famous by negotiating that work would pay for his commute one way. His argument was: "I don't stop thinking about work just because I leave the office and I frequently solve issues on my way home and that's not free".

For some regions, where salaries don't match housing cost, I don't think it's unfair to ask your employer to pay half of your commute. Either you pay a salary that allows relocation, or you pay at least some of the commute time. Again it's not as if work stops just because you leave the office, if you're a developer at least.