Wow, thanks for those, Perna! I don't have time to go through all of them (a lot of them seem to ask for a degree?), but when I get the chance I'll investigate further.

As far as the university offering placement assistance, there was an internship fair recently...that I didn't manage to go to, unfortunately, but looking on the website I couldn't see anything interesting there. Not a lot of it was engineering-related, it was a general fair for the entire university.
The uni that I'm at now would be a nightmare of a commute if I was working here in the summer (we get kicked out of halls at the end of term, so I'd have to come in from home), but there's a uni closer to where I live that's a possibility - hadn't actually thought of that before! Like music lessons, though, it'd still involve customer service, and with any customer service job I always get worried about the possibility of difficult customers...the supermarket job wasn't my idea, it was my dad's.

Thanks, though!