Hello since 30 July 2010, You now have to register a Greek sim Card. This is easily done when you purchase the card from the phone company. You will need your passport. The down side to a greek card , is tax is deducted from your top up value. So you will not get for example 10 € value put on a card.
The weather is April is ok. Daytime in the 20s C , & night time between 10 - 15 C
The exchange rate at the moment is 1.15. Keep in mind this can change on a daily basis

Thank you tpebop how much in tax would you loose on 10euro?

Hello the current level of tax is 12 %
So you would be credited with just under 9 €

Thanks for that info

i've had 3 sim cards since last july and not had to register any of them,all on vodafone. best thing to do if you're on your hols is tell people to text your uk number and then use a 'face' card to call them back from a payphone,they're calling cards that give you around 150 minutes of calling time to UK landlines or around 60 minutes to UK mobiles,you can just buy them in any old supermarket,scratch the panel off the back,dial the number to get onto the service and enter your code from the card,easy,it also tells you how much credit is left before you're connected,there's various brands available,face is just one of the more common,they're all priced around 5 euros.

As for the exchange rate,try google,and whatever it is now is unlikely to be the same come april!

Weather wise it depends what week you go but expect warm days in the high teens to low 20's around lunchtime,probably a couple of thunderstorms,chilly nights and a good few showers,but then you might be lucky,especially later in the month,it may only rain for a few minutes once or twice in the week and then be glorious the rest with mid-20's most of the day. April is a bit hit and miss really,Rhodes tends to get one final huge storm around the 2nd week of may and then just be hot and cloudless until mid september,and no matter what time of year the wind on the west coast (ixia,trianda side)is constant and pretty strong,very nice when it's 40 degrees,keeps the edge off!

If you're down in Lindos expect the temps to be slightly higher in april and then in peak season i think the word 'ferocious' is apt.