I found this today, and I’m sure the last to realise, but it is helpful.
Most people already know about TortoiseSVN’s blame feature, which gives you a view of the code, with the revision/author against each line:
Example (taken from the TSVN Blame page linked above):
However, what you might not have known, is that you can right-click in the Revision/Author area for a given line of code, and select Blame Previous Revision.
This will open another TSVN Blame window, with the selected revision’s changes. You can keep doing this, going back in time to see a picture of the updates that have been layered on a code file.
Of course, this could get a little unwieldy, but if you’re only checking the last few commits, it could prove useful.