So carrying on North from Goldenrod (after running back to check the GTS for status - must link my Wii like on Platinum) I noticed the grass path down the side and thought that I'd take a detour to get the items. After all - the really hidden items like that tend to be TMs and I'm short on moves on a lot of my Pokemon (like lvl 36 Pidgeotto - DLC who has three moves one of which is Tackle).
I popped into the grass after a couple of trainer battles while watching Dr. Who Confidential on the iPlayer and happened to get down to the bottom fairly easily just using the Dratini (learned his new move so can go back in the PokeWalker now) then Pidgeotto (whose mighty tackle destroyed the wild lvl 12 Pokemon). I picked up the TM with a few mins to go to the 30 mark and ran back up to head back to the PokeCentre.
That's when it happened - Ditto attacked! Now I've been breeding Pokemon like mad on Pearl in the past, and transferred all the key players & legendaries across to Platinum so I could trade it in (I don't like to keep too many games). Unfortunately I ignored my boxes full of unhatched eggs and in the process left my two Ditto and my 'incubator' fire Pokemon behind. Not a problem on Plat as I hadn't planned to breed as I had everything I needed, but now on Heart Gold I have no ditto so limited breeding potential.
This ditto represented my ability to give friends the Pokemon that I have stored from Platinum without loosing the originals or resorting to dodgy means (hey - my rival is called Piracy, real trainers don't use ROMs...)
Unfortunately I decided to go straight for the kill with my one Ultra Ball (only level 10 so I thought it was worth a go) and didn't get it. Ditto transformed into Pidgeotto and proceeded to slowly 'tackle' my Pokemon, with the odd 'Feather Dance' and 'Twister' thrown in.
I swapped to less deadly Pokemon right away and chipped away at it's health to put it into the orange. My Geodude was doing great with it's 'rock smash' fighting move taking just enough off each time to be controllable and then it happened. Ditto used Struggle. Ditto Fainted. As DLC only had 3 moves, two of which have low PP he'd burned through all his attacks on GeoDude (i'd spammed defence curl) and run out! This was annoying...
I then decided that this should be an hour long play session - i was still in bed, the TV was playing away and it was the perfect way that a casual player would find a nice chunk of play time on a Sunday. Despite this extension of time 20 mins passed with me running up and down on the same area, returning to the PokeCentre to get better catching Pokemon (using sweet scent too occasionally although it seemed to attract the Drowsee mostly) and using DLC to tackle the wild unwanted ones out of existence. DLC then levelled up, learned Wing Attack & evolved into Pidgeot. I took him out of the lead of the party and when finished put him back in the PW until the next decent move level of Roost at 44. If I manage to switch Pokemon at lunch and walk to work I should still gain 2 levels a day.
A few mins after the evolution I gave up and flipped the DS into sleep mode. I had stuff to do and there were only 10 mins left in the hour anyway.
In the break I managed to breed 9 Squirtle on Platinum while helping my GF to migrate her old laptop onto the new Windows 7 one (works perfectly with network cable) so if you need one let me know in the comments. All male. I set up a team on Platinum of 6 old Pokemon (a few bred starters etc.) to put into Gold ready for later on, and opened Gold to head back to the Pokecentre.
I gave myself 3 more attempts to get a Ditto on the way back - and on the first one he appeared. I swapped to geodude immediately so that he would transform into someone fairly harmless and keep defending. I swapped to Ghastly next and tryd Hypnosis. Worked first time. I then tried a normal PokeBall at full health to the Ditto. Caught first time. I guess that transforming into a fast Pokemon last time hadn't helped matters, but was glad to get my Ditto. I named it 'Breeder' and went back to the Pokecentre to save, trade off the team (resulting in the time being 8hrs 10 mins now) and pit the Pidgeot onto the PW. He really fills the screen so it looks quite good.