i'll throw my two cents in;
I use a combination of saved scripts in a specific folder(lazily using C:\Users\<username>\Documents\SQL Server Management Studio\Projects, and that folder has subfolders and hundreds, probably thousands of files.
for shorter snippets, i use the cliptext feature of editplus, which is a syntax highlighting text editor. it has a boatload of nice features,a nd helps me edit all types of text files, and really powerful macro features.
it has a nice feature where i can give something a short description, and double clicking that description pastes the codeblock associated into the current text document.
it supports multiple groups of snippets, so i have them grouped for every version of SQL(ie sql2005/08/2012.
I grab any interesting snippet form the forums here, and save them constantly; i shudder to think how many snippets i have actually saved over the years. I've never tripped over a size limit for the collection, but have found it sometimes replaced the carat symbol^ that exists in my snippets from version2 to version3 during an upgrade
Lowell