I've enjoyed this thread, so I thought I would add what I know about my Grandad and my great uncles.
My Grandad on my Dads side was RSC (royal army service corps) he joined up in 1915 and saw service in France and worked his way from Ypres back to the Somme in time for the 'big' push. At this point the info I have on him is a bit vague, he was wounded at the Somme and spent a week in no mans land trapped between the lines, the 'water' he drank from a shell hole affected his stomach and he was also wounded with Shrapnel to his abdomen. He was rescued and sent back to Amiens to the hospital, he spent some time there and so the story goes he fell in love (lust!) with a very pretty French nurse.. he wrote to his comanding officer asked permission to marry the lass and permission was granted, this is where thing's take an odd twist, he was being sent to a recovery centre and she went with him to the train, in the crowds of thousands of men they became seperated, he told me that he was holding her hand and the crowd got so thick that her fingers slipped from his, he could'nt sit up as the wounds prevented him doing so... she was pushed away in the crowd and despite his best efforts to get to her he could'nt, he never saw her again! she vanished (maybe killed or posted away) despite this he never forgot her and I remember talking to him about her before he passed away.
My great uncle Frank wasn't so lucky, he served with the RGA (Royal Garrison artillery) and was 17 when he signed on, his service records show he spent time at Woolwich before being posted to France, the Battery he was with was fairly decimated and he was transfered to the Northumbrian Heavy battery, being a Kent boy he felt a bit lonely amongst the Northern lads. Nothing much happens until the 2nd battle of the Somme when his battery was to suffer a gas attack, he never got his mask on in time and his lungs were badly burnt, evacuated to Bolougne he was put on a boat that took him to Newcastle, in the mean time he was posted as a deserter! (idiots didn't even know he had been sent to blighty) My great Grandma had been told he was wounded and I've seen the letter she wrote to his commanding officer asking where he was. (incredibly moving letter, had me in tears) he was sent down to the hospital at Chatham, he even spent a bit of time back home, he fought against the burnt lungs, but sadly he died (it took him two years to die) and is buried in Harty church on the isle of Sheppey, he's the only military grave there in the tiny church yard. (see the link and you can see his grave) I've been to the service on the 11th November many times and find it very moving.
http://thames.me.uk/s00010_files/Harty_Church.jpg