To do this you will need to find out which asset manager(s) is responsible for investing your money, be it in a pension fund, ISA or whatever. Once you have got the name of the asset manager you need to look for the section on their website (if they have one!) dealing with corporate governance. Sometimes you'll find this under the 'about us' header, sometimes it will be in a section about 'responsible investment'.
Once you find the right area you want to look for voting data. Some managers provide one big report for the year, some by quarter, and some by month. And some of course report nothing at all. If the data is produced in a PDF format you should be able to search for the bank names. All the bank AGMs took place in April and May last year so you need to look for those months if it's a monthly disclosure, or Q2 if it's done by quarter.
I'd suggest looking for Alliance & Leicester (still listed last year), Barclays, HBOS, HSBC, Lloyds and RBS. (You could add Standard Chartered, which is also UK-listed but its business is overseas.) If you want to make it really simple, just note down the resolutions that your manager opposed at the 2008 AGMs (if any). If you want to do a bit more digging you could also try and find out how they voted on the RBS takeover of ABN Amro in 2007, and the AGMs in 2007 in general. And don't forget - if you can't find any data log that as well, because the industry claims that it's done a great job in respect of transparency...
Then post the results of your research on your blog and let me know you have done it by posting a comment on this post. I will aggregate links to all posts put up by bloggers who have done the research, and I'll try and persuade Mrs P (a designer you see) to create little button for everyone who participates (Hero of Financial Research First Class or summat like that).
So to get you started, here's my own initial research.
1. The DC pension scheme I am a member is run by the insurer Axa, and the assets invested by Axa Investment Managers. Actually Axa has some good folks working for it, and has a responsible investment team and a dedicated section on its website. But it only discloses very limited data on voting - headline statistics (PDF). So I am unable to identify to find out from their public reporting how they exercised ownership in respect of the banks.
2. Some of our ISA is invested with Gartmore (Paul Myners' old mob actually). I can't even find a corporate governance section on their website from a quick trawl, so no data there apparently.
3. A bit more of our ISA is with Black Rock. It has an SRI docs section here, and a statistical breakdown of votes here (PDF). But because it's just headline stats I can't identify how they voted at the banks either.
So that's 0 out of 3 for the people who invest my money. Can you do any better?