Re: Phoneline Weakpoint
* Silicone grease is an enviro unfriendly last resort - cover the lense then spray around the cam and about 1 foot of nearby wall. Repeat say 2 monthly.
* Fill all nearby holes in wood/brickwork.
* Get one of those "ticklestick" style dusters and mount on the end of a suitably long stick and use it to clear the webs and insects.
Spiders are a fact of life and I personally quite like them. If all else fails then sprayable silicone grease (Maplin do one in the UK - a WD40 branded one I think - not the usual WD40 BTW, its in a green and gold on white can) should be an absolute last resort. You may find that changing the cam location might help as well.