Allow quick add of tags from users own tag cloud as well as "recommended" tags. Current dislayof tags used last time is not enough.
Appears as if you used to allow tagging from drop down list of user created tags. Not sure why you took it away but without it, I find this site cumbersome and lacking necessary functionality for easy sorting of bookmarks. Whether in form of drop down, tag cloud or other, I hope you can bring this feature back!!