Groupon and voucher codes

According to many, Groupon is about to take over the world. The group discount service is the fastest-growing company in the history of the web, and recently secured $950m of investment to fuel its ongoing growth. But what's in it for you? Well, the site relies on lots of people signing up for daily deals, increasing demand to justify huge reductions. Most deals are for more than 50% off, and UK hotel and spa deals pop up daily – a recent search found 60% savings on country hotels in Sussex, and four-day luxury breaks in Morocco down from £1,080 to £268. It's also worth watching voucher code websites such as vouchercodes.co.uk and myvouchercodes.co.uk, for regular coupon offers – for example, 40% off Expedia deals, and 30% off Hotels.com bookings.

Also check out: netvouchercodes.co.uk, livingsocial.com

Cheap flights

The darling of online travel junkies the world over, Kayak.co.uk remains the best flight comparison site in the business. The format is simple: enter your starting point, your destination and your travel dates, then let Kayak do the rest. The site trawls through just about every airline in the world, from obscure regional budget outfits to the big-gun national carriers, to find the cheapest option. The Kayak Buzz feature (Kayak Trends on the mobile app) is a nice touch – displaying the best fares found by fellow users to a range of popular destinations. Toggle this with its brilliant interactive map of cheap routes and you'll find yourself on a £20 return flight to Billund (Denmark) in no time. OK, maybe you don't fancy a weekend in Billund in mid-February, but you get the point.

Also check out: Fly.com, Skyscanner.net, momondo.com

Hotel finders

Over the past few years, hundreds of travel apps have exploded on to the smartphone market. A number of hotel finders are particularly good fun – helping travellers find a last-minute cheap sleep. The Trivago app, which is free to download, is as easy to use as its excellent online site, allowing users to search for the cheapest bed within a variable radius of exactly where they are standing. Alternatively, you can plug in a few parameters – say, a three-star bed for under €60 within a half-hour walk – and it'll spit out whatever it's got. Once you've found your hotel, you can book through the app. The Hotels.com app (also free to download) is well worth a play, too, as it includes hostels alongside hotels, regularly yielding sub-£10 beds in some of the world's most expensive cities.

Also check out: Hotels Near Me app, LateRooms app, Tripadvisor app

Comparison, Comparison, Comparison

In travel – as with just about every consumer market – comparison websites are a very big deal. Which isn't to say they are particularly glamorous. But when it comes to the wholly annoying business of organising travel insurance and car hire, you'd be mad not to spend a little time jumping around the web. For car hire, Traveljungle.co.uk is reliably good, as is comparecarhire.co.uk. For the deeply exciting business of travel insurance, try travelsupermarket.com, comparethemarket.com (if you can banish images of meerkats from your mind) and squaremouth.co.uk. For packages (a complicated comparison field that has yet to really be cracked) look, again, at travelsupermarket.com, and dealchecker.co.uk. Then pour yourself a stiff, well-deserved drink.

Also check out: Insureandgo.com (for insurance), car-hire-centre.co.uk (for car hire)

Guides

A small saving, but a very handy one, in weight as well as cash. The average paperback travel guide costs at least £10,but you rarely pay more than £3 for an app guide. Hundreds have flooded on to the market. Yelp, Spotted By Locals and Lonely Planet apps are all worth a look, displaying tips according to where you are standing. Remember, however, that unless these apps are used in free Wi-Fi zones, the charges can spiral quickly. New guides from Time Out are probably the best, and are usable without connecting to horrifically expensive 3G abroad – the hundreds of tips they contain are native to the app, requiring only your location (which your phone tracks for free). For food hunting, Urbanspoon is a lot of fun and lets you search for local restaurants according to price, and Toptable is a decent app for finding local restaurant offers in the UK.

Also check out: In Your Pocket city apps, Foodspotting

Twitter Deals

Don't be afraid of the Twittersphere. Many, quite understandably, can't be bothered with it. It's a very noisy place, with a lot of chaff disguising tiny grains of wheat. But it's a common misconception that to get the good stuff you need to Tweet yourself. You don't. Hundreds of travel companies use Twitter to broadcast their latest deals and competitions, from TravelZoo's ever-handy top 20 deals of the week to Skyscanner's frequently tempting deal of the day. You don't need to be signed up to see them. Because we're nice, we've rounded up some of the most reliable travel-deal Twitterers on @GuardianTravel's Twitter deal list, where you'll find deals (and occasional other bits and bobs) from 13 companies all in one place.

Also check out: @STATravelUKDeal, @UKTraveloffers, @Letsgo2holidays

5 more quick tips

• Free Wi-Fi finder app: Lists free Wi-Fi spots in more than 10,000 locations worldwide.
• Skype app on your phone: Turns your phone into a free calls device – when in Wi-Fi zones.
• Parkatmyhouse.co.uk: Park at houses near airports at less than half the price of official car parks.
• Flycheapo.com: Easy-to-use directory of European budget flight routes.
• SitOrSquat app: Finds free public toilets in thousands of destinations across the globe