Redirection of Post suggestions please!

[#1]

OK, some of you probably know that I'm moving house soon (pending solicitors not being on holiday etc)
We are temporarily moving into a friends home before moving into our new home later next (hopefully!) month.
So, what are your thoughts on the best way to handle mail redirection?
Our friends are moving out next week, so when we move out of their place, we won't have access again to their place to collect mail thats there that shouldn't be.
I was thinking maybe setting up a PO box, then informing Royal Mail to redirect all mail into the PO Box.
Once we are in the new place, we can then start changing addresses on things to our new address, and gradually phasing out the amount of stuff coming via the PO box.
We would never give anybody the PO Box address, except perhaps the people who are buying our house, in case anything did get delivered still. Once we were in our new home we would ask the people buying ours to forward any remaining stray mail to our new home.
Does this sound feasible/long winded/plain stupid?
Any better suggestions?
We would rather not ever have mail delivered to our friends house if possible on the basis that we will live there after they've left, but we will have no relationship with the incoming purchasers or renters of their property. (And we have experienced the PO getting confused with re-directs in the past)
EDIT: For Bad SP..

[#2]

Hi James_G
That would be the best way set up a PO box, then inform Royal Mail to redirect all mail into the PO Box.

[#3]

The cost of a PO box seem an expensive way to go. Have you thought of redirecting mail to friends, parents or your place of work?

[#4]

My parents redirected our post to my Grandmothers.
They even forged my signature !!!

[#5]

Work sounded good to me.

[#6]

Cancelling the first redirect and replacing it with a second would cost less than a PO Box!

[#7]

Yep, but that involve re-directing mail to our friends house, which we don't want to do...
Its also one of the suggested methods on the PO website, but neither the lady in our local post office (Main post office/sorting office) nor the lady I spoke to on the phone are able to say with conviction that it actually works as it should.
Apparently eventually it would work, but there are all sorts of messy overlaps, and then we have the risk of mail ending up in two places it shouldn't, one of which we would be unable to access.

If they have no faith, how can they hope to persuade me? (In actuality I get very little mail anyway these days...)

[#8]

From what I recall of the Royal Mail, re-directing takes some time to come into effect.  initially you need (I think) to fill out one of their re-direction forms, for the appropriate amount of time .... 1  month.... 3 months..... 6 months.... (all with increasing amount of cost involved) and this needs to be done at least 1 month in advance of the start date.... depending on how much mail you "think" you may receive (and who is likely to send you mail) 1 month seems a short period of time, but 3 months may be too long. and 6 months ......
As you mentioned, they did not convince me when I tried to find out how "effective" the re-direct service is..... I think it basically relies on the regular sorter of your round,/area, remembering that there is a re-direct notice in effect for your address, and if it doesn`t go through him, it is likely to be delivered as per the address on the envelope... 
Do you know the postie that delivers to your present home address? 
you could get a few pages of sticky labels pre-printed with your new address/ relative/work address, and leave them in a nice dry place near the front door, and you may be able to persuade him/her to stick a label  on anything that comes for you after you have moved out....

[#9]

I recently setup a redirection and it seems to be working flawlessly.  It's a week notice they need.  The redirection is actually done almost completely manually... the mail still ends up at the closest delivery office to the address on the envelope - and is then sorted into the 'delivery group' to be delivered by the postie.  At that point all mail is checked against a list of redirections setup on that delivery group and the post is manually relabelled with the new address and put back into the system.  So I guess it depends how good your local delivery office are.  Mine is in Exeter.

[#10]

5 days notice Shutter, but as you say it relies upon the chaps at the local sorting office looking up the re-directs/remembering, expecting this to work twice for each envelope seems optimistic at best.
The converse applies when you cancel one too - it relies upon the sorting office peeps checking that its ended, or not remembering its in place.
The posties do a good job, but its a heck of a lot to ask.
The other trouble is that at the time of moving you get all sorts of post, without necessarily knowing whether something that should have arrived hasn't gone astray.
Perhaps a single re-direct to the in-laws for 3mths might be in order in terms of simplicity and reliability.
(In conjunction with either sticky address labels for any that get through.)

[#11]

I previously had a redirection in place with mixed results.  If it wasn't for me moving 3 months before the house sale completed I would probably have thought it was working flawlessly..
As I still had access to the house,  the reality was slightly different.  I'd estimate that at least a quarter of the mail was not redirected.
Even after being contacted a few time, mail still kept being delivered to the old address.