If you want to take your bike on holiday with you - we highly recommend it; beats reading endless Mills and Boon on the beach - then you ought to invest in a proper bag to transport your pride and joy in.
This offering from Vaude is 4ft long, 3ft tall and 1ft wide, big enough to take most hardtails and XC full sussers with only the wheels removed and slid into the internal wheel pockets. Bigger DH type rigs with longer wheelbases might need the fork dropped out to get them in, but it'll depend on the bike you have.
The bag is padded to provide protection, and although it's not the thickest padding we've encountered in big bag land, it's enough unless you get the real gorilla baggage handler.
The biggest plus is the addition of twin wheels on one end, which enables it to be towed through airports without you having to cart the thing about by hand or wedge it on a trolley. Add an internal tool pocket and external address pocket and you're good to go. All we need now is a holiday...