How to use a remote node?

If you don't have the 6-8 Gb of RAM presently needed to comfortably use your computer whilst synchronising the blockchain with bitmonerod, you can use a remote node, like hegemoon's node. This means you don't have to run bitmonerod anymore (this does negatively affect decentralisation, but not much)
For Linux:

./simplewallet --daemon-address xmr1.coolmining.club:5012 --wallet-file ./wallet.bin

Change ./wallet.bin with the path of your wallet (here, it means "the wallet is called wallet.bin and is in the same location as simplewallet). The code above assumes your working directory (use pwd or ls to check) is the one where both your wallet and your simplewallet binary are located.
The daemon host and port are hegemoon's, but you can use another one.
Tip1
You can install then use rlwrap to cycle through commands on the Linux version (no need for this in the Windows version)

sudo apt-get rlwrap
rlwrap ./simplewallet --daemon-address xmr1.coolmining.club:5012 --wallet-file ./test1.bin

Tip2
To be sure to always be on the right directory for launching simplewallet, just add a command to go to the right directory

cd /bitmonero/build/release/bin/ && ./simplewallet --daemon-address xmr1.coolmining.club:5012 --wallet-file ./test1.bin

Tip3
You can combine both:

cd /bitmonero/build/release/bin/ && rlwrap ./simplewallet --daemon-address xmr1.coolmining.club:5012 --wallet-file ./test1.bin