The problem is that, for now, the web address for a Google+ profile ends in a really long, nearly impossible to remember, number. For example, my profile on Google+ is located at https://plus.google.com/116362374400836482520/. The profile for Guy Kawasaki is a https://plus.google.com/112374836634096795698/. The profile for Barak Obama https://plus.google.com/110031535020051778989. You get the idea.
Not exactly easy to use but there is a work-around.
Facebook had the same problem for awhile but then allowed users to register claim 'vanity' URLs. So, as an example, my profile on Facebook went from something similarly impossible to remember to https://www.facebook.com/blawler. Much more friendly. There are also some tricks to get nicer URLs in Windows Live.
The "trick" you can try in Google+ is that sometimes the person's Google Profile URL re-directs to the person's Google+ URL. So, for example, my Google Profile is at https://profiles.google.com/balawler. But, since the Google+ roll-out, that URL no longer shows the old Google Profiles page for me but now re-directs to my Google+ page. Also, for better or worse, I didn't have to do anything for this re-direct (no settings in Google+) it is just something Google has setup automatically. Yea!
Bad news? Yep, there is alway some of that. The bad news is that I've combed over my GMail contacts trying this and found this works for some Google users.... but not for others. Sometimes replacing the "username" in "firstname.lastname@example.org" or "username.blogspot.com" or "youtube.com/user/username" into "profiles.google.com/username" will re-direct for some Google users into that user's Google+ profile... and for other Google users it doesn't. I don't know why. Could be if that individual didn't sign up for the Google+ service... or never used Google Profiles. Or, as likely, I vaguely recall that Google Profile used to have long URLs and I think there was an option to request a short name (e.g. the "balawler" part). Maybe that makes a difference.
Anyway, as they say, "your mileage may vary", use at your own risk, etc.