Interesting little piece of advice here for you - it has come to our attention at Orchid Box that Google are now recommending the avoidance of the "plus" sign in - that is to say "+" - in URLs.
Generally speaking, the plus sign is used as shorthand for a space in query parameters, but while it can be used in such a way in URLs, it isn't a good idea. The plus sign is sometimes transformed into a space or to "%20" which can cause problems for the spiders crawling your site, hence causing issues with indexation. URLs with spaces are often confusing to theses spiders, especially with forums and blogs where the URL is automatically recofnised and converted into a link.
So what to do instead? Avoid the "plus" sign and use another key that is acceptable for the Google spiders and avoids any confusion (bless them, they're simple minds at heart) - you could use "-", "_", "." or "~". That is to say dash, underscore, full stop or squiggly thing.
Apologies as well - has there ever been such a wealth of punctation in a row as above? It reminds me of the sentence "James, while John had had "had" had had "had had"; "had had" had had a better effect on the teacher." Confused? Enlighten yourself...