By Jennifer Hill, Personal Finance Correspondent

LONDON (Reuters) - Hunting for that perfect Christmas gift for someone who has everything? Well, why not give your loves ones something that indulges their passions and could also net them a tidy profit?

Alternative investments are big business, and are no longer the preserve of the super-rich. While most people will have heard of investment in art and antiques, there is a myriad of other items -- coins, royal and sporting memorabilia, fine wines -- that can be invested in for less outlay.

Britain's over-50s are becoming serial collectors, and have spent 2.5 billion pounds on collectibles in the past five years, research from Direct Line shows.

Top items to collect include out-of-circulation money, commemorative royal memorabilia, pop memorabilia, advertising merchandise from the 1950s and 60s, antique glass and toys.

A third of collectors sees their stash as an investment to hand down to younger generations, while a quarter believe they are hoarding tomorrow's antiques.

"We're starting to see the new generation of antiques emerge in the form of comics and pop memorabilia from the 60s, which many people may have lying around in their attics gathering dust," says Jamie Breese, a collectables expert for ITV.

Returns can prove lucrative. A tenth of those polled by Direct Line said they consider alternative assets to be more worthwhile than shares, and the average collector has seen the value of their investment rise four-fold in the past five years.

Owners of coins from the early 20th century can expect to receive up to 150 pounds for a five-pound note from 1907, according to Millers Collectibles Price Guide 2007, while royal memorabilia, such as plates or mugs from the Queen's coronation in 1953, can fetch more than 200 pounds.