Well, whatever technology or product you will decide to use, they will not be the problem. All knowledge which is not sufficiently well shared at the coffee machine needs attention.
- Attention when actually writing it (be it a document on a network drive, a wiki-page, a SharePoint server, whatever).
- Attention to categorize it (by linking, tags, web-pages, whatever...).
- Attention to keep it up-to-date (by individual on-demand or scheduled effort,).
Whatever you use, no technology will help with this. For this you need to motivate the team to write things down, read up things in the repository up first before phoning (and interrupting) a bunch of other team-members, and correct things if they are wrong.
From my experience, SharePoint and Wikis perform about the same. You need to beat people to use it, until they experience that they want to use it, because they will at some point experience that such type of information sharing can save time -- their time.
As you have already a habit of sharing information, this may not be so much of a hard problem for you. I'd recommend that one (or a few, better less than too many) provide some (spare) initial structure, and then let the fill-in begin. As no perfect categorization exists, you should not worry too much about it.
