Tipping protocols are often debated on this board. It also highly varies from country to country, as mentioned by swise.. In some countries people are insulted if you leave a tip (which I'll never understand) and in some places (like the US) people live off of the tips they earn.

Last year I was on the road almost 250 nights. Lets assume, on the average, I give out $5 in tips per day of travel. This does not include tips added to meals, but does include taxis, shuttle drivers, valet, housekeeping, bellmen and the occasional hostess at a restaurant. That adds up to $1250. That is an incredible expense out of my own pocket for travel my company is requiring me to do. My fellow employee who sits at his desk all year in his home office isn't incurring this expense. I don't think it is unreasonable to expect an employer to reimburse a reasonable amount of tips.