A feature similar to the current Auto tag from Web feature
Have your songs playing and search (a preselected search site) for song details. Similar to Auto tag from Web, just it is in the Now Playing window itself. If a match is found, the currently playing song line is turned yellow with the modified tags (again, similar to Auto-tag).. have a check box next to the song which would save the updated tags.
Would save a lot of time and would be very convenient too.
Script Request / Feature Request
Not for me as I don't ever play my tracks before they're tagged (aside from the occasional typo), but perhaps someone would find it useful.

MM Gold 3.0.3.1183 : Vista HP SP1 (x86) : Zen Stone (2GB)
Zekton: An original MM3 skin by Eyal.
Scripts in Use: Add/Remove PlayStat | Auto Album DJ | AutoRateAccurate | Backup
Case & Leading Zero Fixer | Classification & Genre Changer | Clean Scripts.ini | Clear
Field | Custom Report | Discogs Auto-Tag Web Search | Forget Crossfade | Invert
Selection/Select None | Last 100... | Lyricator | Lyrics to Instrumental | MonkeyRok
MusicBrainz Tagger | My Custom Nodes | Now Playing Art Node | Play History & Stats
Right Click for Reports | Right Click for Scripts | Right Click for Web | Stop After Current
WebNodes